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eval_min_detectable_gap

Calculate the smallest accuracy gain over a baseline that an eval with n test cases can reliably detect, enabling you to sanity-check whether an existing eval set is adequately powered.

Instructions

Smallest accuracy improvement over baseline_acc that an eval with n test cases can reliably detect. Use this to sanity-check an existing eval set.

Input Schema

NameRequiredDescriptionDefault
nYes
alphaNo
powerNo
pairedNo
discordanceNo
baseline_accYes

Schema Changelog

Changes observed during successful MCP inspections.

  1. First observedv0.1.0

TDQS

C2.9/5.0
Behavior2/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations exist, so the description carries the full burden, and it discloses almost nothing behavioral: not that this is a pure read-only computation, not the statistical assumptions baked into the defaults (alpha=0.05, power=0.8, paired test), and not how the result is expressed (accuracy points vs. proportion). Only the headline behavior is stated.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Two tight sentences with the definition front-loaded and the usage hint second; nothing is padded. The only cost is that brevity here is partly under-specification rather than efficiency.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness2/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

No output schema, no annotations, and 0% schema coverage for 6 parameters means the description must do the heavy lifting, and it does not: return-value semantics, the paired/discordance interaction, and the effect of alpha/power are all unaddressed.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters2/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0% across 6 parameters, and the description only touches the two required ones (n, baseline_acc) by name. The statistically consequential parameters — alpha, power, paired, discordance — are completely unexplained, leaving the agent to guess at semantics that strongly affect the answer.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

Names a specific computed quantity (minimum detectable accuracy improvement) in terms of two named inputs, which is precise enough for an agent to recognize the tool's role in an eval-design toolkit. It does not explicitly contrast itself with eval_sample_size or the compare_* siblings, so the differentiation is left implicit.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

'Use this to sanity-check an existing eval set' gives one concrete scenario, which is more than nothing. But there is no statement of when NOT to use it (e.g., to plan a new eval, use eval_sample_size instead) and no mention of the sibling tools at all.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.