Ask Less, Ask Better: Allocating User Attention in Proactive LLM Agents with Interruption Budgets
Organizations: Columbia University · Oracle AI
Abstract
LLM agents can ask clarifying questions to complete tasks, but answering each question demands users' time and effort. Existing evaluations typically measure this burden by counting questions, treating necessary and avoidable questions equally. We propose an evaluation protocol that distinguishes how often agents ask from how well they ask. An interruption budget limits the number of questions, while a user-attention cost charges extra for questions that are hard to read or not worth asking, as rated by a human-validated LLM judge. Beyond question counts, this cost captures perceived effort: on conversation pairs with the same number of questions, human annotators agreed with the cost on which conversation required more effort 75% of the time. Across eight LLMs and four customer-service domains, limiting agents to one to three questions reduces user-attention cost by 36-73% while keeping 86-94% of the task reward they earn with unlimited questions. At the same budget, reviewing each question against the memory of users' earlier answers cuts attention cost by another 13% with little reward loss and yields more valuable questions. Models also differ sharply in how well they ask: at the same user-attention cost, the most efficient models gain more than twice as much reward from their questions as the others. These results show that asking less and asking better are distinct goals, and that evaluations of proactive agents should measure both.
Figures & tables
| Reading effort : five dimensions, each rated 1–5 | |
|---|---|
| 1. Goal clarity | Is it clear what the agent needs and why? |
| 2. Single ask | One answerable thing, not several bundled? |
| 3. Answer effort | Answerable without decoding jargon? |
| 4. Actionability | If it asks for an action, is it concrete? |
| 5. Conciseness | As short as possible while still clear? |
| Question value : high only if all four criteria hold | |
| Customer service | Interactive research | |||||
|---|---|---|---|---|---|---|
| Method | ||||||
| Unrestricted | 49.4 | 29.5 | 63.5 | 32.7 | 19.0 | 64.3 |
| Frugal prompt | 47.0 | 24.9 | 65.7 | 31.7 | 15.8 | 67.0 |
| VoI gate | 47.4 | 30.7 | 58.6 | 32.3 | 18.4 | 67.3 |
| Budgeted | 44.7 | 13.7 | 69.4 | 29.6 | 16.0 | 68.0 |
| Budgeted + MGR | 43.9 | 12.0 | 71.7 | 28.7 | 15.1 | 69.8 |
| Annotator judgment | ||
|---|---|---|
| Pairs (60 each) | Question burden | Overall burden |
| Different counts | ||
| Equal counts | ||
| value alone | ||
| effort alone | ||
| question words | ||
| Observed | Equal cost | |||
|---|---|---|---|---|
| Policy | ||||
| Budgeted | 13.7 | 69.2 | – | – |
| Budgeted + Review | 12.8 | 68.6 | ||
| Budgeted + Review + Summary | 12.3 | 70.6 | ||
| Budgeted + MGR | 12.0 | 71.5 | ||
Appendix figures & tables26 assets
Supplementary material from the paper’s appendix.
Appendix
| Dataset | Total | Dev | Test |
|---|---|---|---|
| Customer service | |||
| Retail | 114 | 23 | 91 |
| Airline | 50 | 10 | 40 |
| Telecom | 114 | 23 | 91 |
| Ambiguous WebShop | 200 | 40 | 160 |
| Interactive research | |||
| Requests | User-attention | at | Reviews | Vetoed | Fixed message | ||
| Policy | per session | cost | Reward | equal cost | per session | (%) | (%, -bench) |
| Unrestricted | 3.12 | 31.0 | 58.9 | – | – | – | 0.0 |
| VoI gate as run ( ) | 3.40 | 34.6 | 57.3 | – | – | – | 0.0 |
| VoI gate, enforced veto ( ) | 1.73 | 17.2 | 51.0 | ∗ | 6.4 | 71 | 6.9 |
| VoI gate, enforced veto ( ) | 0.44 | 4.1 | 44.8 | ∗ | 8.1 | 94 | 12.0 |
| Budgeted ( ) | 0.94 | 8.5 | 50.9 | 0 | – | – | 6.2 |
| Requests | User-attention | Question | at | Reviews | Vetoed | Fixed message | |||
| Policy | per session | cost | Reward | value | equal cost | per session | (%) | (%, -bench) | |
| 1 | Budgeted | 0.94 | 8.5 | 50.9 | 78.1 | 0 | – | – | 6.2 |
| Budgeted + VoI gate | 0.91 | 8.8 | 46.5 | 67.8 | ∗ | 1.2 | 20 | 5.4 | |
| Budgeted + MGR | 0.83 | 7.4 | 49.3 | 79.3 | – | – | 6.9 | ||
| 2 | Budgeted | 1.63 | 15.4 | 54.5 | 73.1 | 0 | – | – | 3.8 |
| Budgeted + VoI gate | 1.61 | 16.1 | 50.3 | 64.6 | ∗ | 2.1 | 21 | 4.5 |
| Symbol | Meaning |
|---|---|
| , | Interaction session; step index |
| Policy: ask, call a tool, or respond | |
| Task reward in | |
| Delivered discretionary request message | |
| All such requests in | |
| Interruption budget, |
| Comparison | Readability | Question value |
|---|---|---|
| Human–human | 92.5 [86.1, 97.6] | 87.5 [79.0, 94.9] |
| Judge–annotator (mean) | 90.0 [84.0, 95.6] | 90.0 [84.2, 95.1] |
| Second judge (mean) | 71.2 [61.3, 80.6] | 76.9 [68.5, 85.0] |
| Judge–annotator agreement by benchmark | ||
| -bench ( ) | 90.0 | 93.8 |
| WebShop ( ) | 90.0 | 86.2 |
| Comparison | Agreement (%) | Cohen’s |
|---|---|---|
| Three labels | ||
| Human–human | 90.0 [84.0, 95.0] | 0.84 [0.73, 0.92] |
| Classifier–A1 | 90.0 [84.0, 95.0] | 0.84 [0.74, 0.92] |
| Classifier–A2 | 92.0 [87.0, 97.0] | 0.87 [0.77, 0.95] |
| Classifier–human | 91.0 [86.5, 95.5] | 0.85 [0.77, 0.92] |
| Discretionary versus non-discretionary | ||
| Question value | Reading effort | |
| Agreement on the same questions | ||
| Questions | 1989 | 1989 |
| Mean, first judge | ||
| Mean, second judge | ||
| Rank correlation | ||
| Mean abs. difference | ||
| Cost definition | Budgeted, | Budgeted, | Budgeted, | MGR, mean –3 |
|---|---|---|---|---|
| Messages | 70.4 [68.9, 71.7] | 49.0 [46.7, 51.1] | 33.2 [30.6, 35.7] | 10.9 [9.9, 12.0] |
| Atomic questions | 67.8 [66.1, 69.3] | 47.1 [44.8, 49.4] | 31.7 [29.2, 34.0] | 11.4 [10.4, 12.5] |
| Count + reading effort | 71.0 [69.5, 72.4] | 49.9 [47.6, 52.1] | 34.1 [31.5, 36.5] | 11.3 [10.3, 12.4] |
| Full discretionary cost | 73.0 [71.6, 74.3] | 51.9 [49.7, 54.0] | 35.7 [33.1, 38.2] | 12.7 [11.6, 13.8] |
| Full cost + exempt requests | 37.7 [35.7, 39.8] | 26.5 [24.5, 28.5] | 17.3 [15.3, 19.2] | 4.5 [3.7, 5.4] |
| Policy | Messages | Atomic questions | Exempt requests | Bundled (%) |
|---|---|---|---|---|
| Unrestricted | 2.84 [2.68, 2.99] | 5.39 [5.06, 5.72] | 3.44 [3.20, 3.67] | 52.5 [51.0, 54.0] |
| Frugal prompt | 2.43 [2.30, 2.56] | 4.20 [3.95, 4.46] | 3.66 [3.42, 3.90] | 47.6 [46.1, 49.1] |
| VoI gate (original) | 2.91 [2.74, 3.09] | 4.56 [4.29, 4.84] | 3.67 [3.43, 3.90] | 35.0 [33.7, 36.2] |
| Budgeted, | 0.84 [0.83, 0.85] | 1.74 [1.69, 1.79] | 3.70 [3.46, 3.94] | 64.1 [62.4, 65.8] |
| Budgeted, | 1.45 [1.42, 1.48] | 2.85 [2.75, 2.95] | 3.65 [3.41, 3.89] | 57.7 [56.1, 59.2] |
| Budgeted, | 1.90 [1.85, 1.94] | 3.68 [3.53, 3.83] | 3.66 [3.42, 3.90] | 55.2 [53.5, 56.8] |
| Wide window minus | ||
| Budgeted | Budgeted | |
| + Review | + MGR | |
| User-attention cost (%) | ∗ | |
| Question value | ∗ | ∗ |
| Reward | ||
| Reward at equal user-attention cost | ||
| –3 | ||||
| Elicitation recall (%), eight models | ||||
| Budgeted | ||||
| Budgeted + Review | ||||
| Budgeted + Review + Summary | ||||
| Budgeted + MGR | ||||
| Differences in recall (points) | ||||
| Method | Main | BrowseComp | ||||||
|---|---|---|---|---|---|---|---|---|
| Unrestricted | 50.8 | 33.3 | 55.7 | 63.2 | 32.7 | 19.0 | 47.7 | 64.3 |
| Frugal prompt | 48.2 | 28.4 | 55.5 | 65.9 | 31.7 | 15.8 | 48.0 | 67.0 |
| VoI gate | 49.0 | 35.2 | 53.9 | 58.5 | 32.3 | 18.4 | 47.6 | 67.3 |
| Budgeted | 46.0 | 14.6 | 58.2 | 68.4 | 29.6 | 16.0 | 46.5 | 68.0 |
| Budgeted + MGR | 44.5 | 12.9 | 57.7 | 70.8 | 28.7 | 15.1 | 46.1 | 69.8 |
| Guarded | Original | |||||||
| Policy | ||||||||
| GPT-6-Astra | ||||||||
| Unrestricted | 0.783 | 3.135 | -0.059 | 8.374 | 0.883 | 1.676 | 0.433 | 8.416 |
| Budgeted ( ) | 0.583 | 1.240 | 0.250 | 8.114 | 0.858 | 1.026 | 0.583 | 8.362 |
| Budgeted + MGR ( ) | 0.700 | 1.106 | 0.403 | 8.569 | 0.833 | 0.997 | 0.566 | 8.801 |
| Budgeted ( ) | 0.750 | 2.066 | 0.195 | 8.572 | 0.867 | 1.520 | 0.458 | 8.387 |
| Method | Retail | Airline | Telecom | WebShop | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| No-ask | 0 | 0.58 | – | – | – | 0.70 | – | – | – | 0.49 | – | – | – | 0.29 | – | – | – |
| Unrestricted | 0.73 | 3.36 | 0.62 | 8.86 | 0.88 | 3.88 | 0.77 | 8.19 | 0.81 | 2.39 | 0.74 | 7.31 | 0.56 | 2.17 | 0.49 | 6.38 | |
| Frugal prompt | 0.68 | 1.93 | 0.62 | 9.60 | 0.81 | 2.61 | 0.73 | 9.10 | 0.84 | 2.01 | 0.78 | 8.03 | 0.55 | 1.66 | 0.50 | 7.25 | |
| VoI gate | 0.69 | 3.92 | 0.57 | 8.28 | 0.88 | 4.81 | 0.74 | 7.52 | 0.81 | 2.79 | 0.72 | 6.81 | 0.56 | 2.71 | 0.48 | 6.29 | |
| Budgeted | 1 | 0.65 | 1.27 | 0.61 | 8.57 | 0.80 | 1.15 | 0.77 | 8.75 | 0.65 | 1.20 | 0.62 | 7.81 | 0.56 | 1.50 | 0.52 | 6.84 |
| Method | Retail | Airline | Telecom | WebShop | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| No-ask | 0 | 0.52 | – | – | – | 0.57 | – | – | – | 0.30 | – | – | – | 0.23 | – | – | – |
| Unrestricted | 0.66 | 5.68 | 0.49 | 6.70 | 0.68 | 5.46 | 0.52 | 6.61 | 0.36 | 3.61 | 0.25 | 6.42 | 0.44 | 2.42 | 0.37 | 6.41 | |
| Frugal prompt | 0.64 | 4.24 | 0.51 | 7.22 | 0.64 | 4.16 | 0.52 | 6.93 | 0.27 | 2.26 | 0.21 | 5.92 | 0.39 | 1.84 | 0.33 | 7.16 | |
| VoI gate | 0.66 | 7.15 | 0.45 | 5.51 | 0.60 | 6.86 | 0.39 | 5.73 | 0.31 | 2.69 | 0.23 | 6.50 | 0.42 | 3.11 | 0.32 | 6.01 | |
| Budgeted | 1 | 0.57 | 1.31 | 0.53 | 7.58 | 0.64 | 1.24 | 0.60 | 7.74 | 0.26 | 1.21 | 0.22 | 7.82 | 0.38 | 1.32 | 0.34 | 7.33 |
| Method | Retail | Airline | Telecom | WebShop | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| No-ask | 0 | 0.52 | – | – | – | 0.49 | – | – | – | 0.24 | – | – | – | 0.26 | – | – | – |
| Unrestricted | 0.71 | 7.42 | 0.48 | 5.76 | 0.53 | 8.71 | 0.27 | 5.71 | 0.29 | 8.62 | 0.03 | 6.73 | 0.42 | 2.12 | 0.36 | 7.15 | |
| Frugal prompt | 0.66 | 7.07 | 0.45 | 5.75 | 0.53 | 7.67 | 0.30 | 6.00 | 0.26 | 6.42 | 0.07 | 6.87 | 0.36 | 1.30 | 0.32 | 7.44 | |
| VoI gate | 0.69 | 8.05 | 0.45 | 5.50 | 0.57 | 9.73 | 0.27 | 5.11 | 0.30 | 7.60 | 0.08 | 5.78 | 0.39 | 2.94 | 0.30 | 6.20 | |
| Budgeted | 1 | 0.51 | 1.31 | 0.47 | 8.05 | 0.43 | 1.43 | 0.39 | 7.28 | 0.25 | 1.30 | 0.21 | 8.12 | 0.39 | 1.13 | 0.36 | 7.79 |
| Method | Retail | Airline | Telecom | WebShop | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| No-ask | 0 | 0.05 | – | – | – | 0.35 | – | – | – | 0.05 | – | – | – | 0.25 | – | – | – |
| Unrestricted | 0.08 | 4.67 | -0.06 | 4.43 | 0.42 | 5.61 | 0.26 | 5.51 | 0.07 | 2.64 | -0.01 | 4.08 | 0.24 | 0.31 | 0.23 | 6.24 | |
| Frugal prompt | 0.08 | 4.51 | -0.06 | 4.26 | 0.42 | 5.55 | 0.25 | 5.03 | 0.08 | 3.57 | -0.03 | 3.73 | 0.22 | 0.11 | 0.21 | 7.38 | |
| VoI gate | 0.11 | 3.96 | -0.01 | 4.52 | 0.40 | 5.41 | 0.24 | 4.70 | 0.05 | 1.57 | 0.00 | 4.28 | 0.24 | 0.13 | 0.23 | 5.92 | |
| Budgeted | 1 | 0.11 | 1.28 | 0.08 | 4.96 | 0.38 | 1.33 | 0.34 | 6.86 | 0.06 | 1.14 | 0.03 | 4.66 | 0.26 | 0.55 | 0.24 | 6.76 |
| Method | Retail | Airline | Telecom | WebShop | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| No-ask | 0 | 0.38 | – | – | – | 0.38 | – | – | – | 0.68 | – | – | – | 0.25 | – | – | – |
| Unrestricted | 0.76 | 12.73 | 0.38 | 5.25 | 0.48 | 12.21 | 0.12 | 5.27 | 0.65 | 4.91 | 0.50 | 5.76 | 0.39 | 1.12 | 0.36 | 7.72 | |
| Frugal prompt | 0.74 | 11.50 | 0.40 | 5.31 | 0.47 | 11.10 | 0.13 | 5.47 | 0.66 | 4.87 | 0.51 | 5.55 | 0.35 | 0.86 | 0.32 | 7.79 | |
| VoI gate | 0.67 | 14.66 | 0.23 | 4.77 | 0.44 | 12.24 | 0.07 | 4.91 | 0.64 | 4.25 | 0.52 | 5.28 | 0.37 | 1.10 | 0.33 | 7.34 | |
| Budgeted | 1 | 0.46 | 1.69 | 0.41 | 4.23 | 0.28 | 1.42 | 0.24 | 7.72 | 0.67 | 1.56 | 0.63 | 7.01 | 0.40 | 1.08 | 0.37 | 7.73 |
| Method | Retail | Airline | Telecom | WebShop | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| No-ask | 0 | 0.05 | – | – | – | 0.53 | – | – | – | 0.18 | – | – | – | 0.25 | – | – | – |
| Unrestricted | 0.10 | 2.28 | 0.03 | 6.23 | 0.51 | 0.12 | 0.50 | – | 0.18 | 2.19 | 0.11 | 5.44 | 0.38 | 2.68 | 0.30 | 6.12 | |
| Frugal prompt | 0.10 | 2.26 | 0.03 | 6.74 | 0.49 | 0.38 | 0.48 | – | 0.18 | 0.82 | 0.15 | 4.91 | 0.36 | 1.79 | 0.30 | 6.66 | |
| VoI gate | 0.07 | 1.93 | 0.02 | 6.23 | 0.51 | 0.17 | 0.50 | – | 0.18 | 0.95 | 0.15 | 5.43 | 0.36 | 3.10 | 0.27 | 5.38 | |
| Budgeted | 1 | 0.07 | 0.48 | 0.05 | 7.64 | 0.51 | 0.02 | 0.51 | – | 0.18 | 0.72 | 0.15 | 6.41 | 0.31 | 1.45 | 0.27 | 6.01 |
| Method | Retail | Airline | Telecom | WebShop | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| No-ask | 0 | 0.35 | – | – | – | 0.62 | – | – | – | 0.41 | – | – | – | 0.07 | – | – | – |
| Unrestricted | 0.80 | 5.15 | 0.65 | 6.92 | 0.90 | 6.43 | 0.70 | 6.72 | 0.56 | 3.19 | 0.47 | 6.60 | 0.38 | 1.55 | 0.33 | 7.20 | |
| Frugal prompt | 0.83 | 4.80 | 0.68 | 7.18 | 0.87 | 5.25 | 0.71 | 7.13 | 0.54 | 2.74 | 0.46 | 6.08 | 0.33 | 1.40 | 0.29 | 7.46 | |
| VoI gate | 0.77 | 5.69 | 0.60 | 6.56 | 0.84 | 6.44 | 0.64 | 6.31 | 0.52 | 2.57 | 0.45 | 6.41 | 0.39 | 1.61 | 0.34 | 7.18 | |
| Budgeted | 1 | 0.59 | 1.23 | 0.55 | 9.08 | 0.72 | 1.28 | 0.68 | 7.92 | 0.45 | 1.10 | 0.42 | 8.11 | 0.41 | 1.43 | 0.37 | 7.39 |
| Method | Retail | Airline | Telecom | WebShop | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| No-ask | 0 | 0.25 | – | – | – | 0.54 | – | – | – | 0.23 | – | – | – | 0.24 | – | – | – |
| Unrestricted | 0.60 | 5.64 | 0.43 | 5.81 | 0.62 | 4.22 | 0.49 | 6.19 | 0.28 | 5.78 | 0.11 | 6.59 | 0.35 | 2.31 | 0.28 | 6.63 | |
| Frugal prompt | 0.54 | 5.64 | 0.37 | 5.49 | 0.56 | 3.38 | 0.46 | 6.35 | 0.27 | 4.44 | 0.14 | 6.73 | 0.34 | 1.34 | 0.30 | 7.29 | |
| VoI gate | 0.51 | 6.91 | 0.30 | 4.90 | 0.62 | 4.57 | 0.48 | 5.31 | 0.25 | 5.01 | 0.10 | 5.10 | 0.34 | 2.83 | 0.25 | 6.01 | |
| Budgeted | 1 | 0.36 | 1.34 | 0.32 | 7.26 | 0.59 | 1.03 | 0.56 | 8.20 | 0.26 | 1.37 | 0.22 | 7.27 | 0.33 | 1.38 | 0.29 | 6.80 |
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Large language model agents use language models to plan, use tools, and act across multi-step tasks and environments.
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