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

The description goes beyond the readOnlyHint and openWorldHint annotations by explaining the permutation test methodology and its purpose—to prevent a flattering subset from passing as a regime effect. It also notes that buckets below minSample are flagged unusable (via schema). It does not contradict any annotation and adds meaningful behavioral context about the statistical safeguards.

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

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

The description is three sentences with no wasted words. The first sentence states the core function, the second explains the permutation test, and the third gives usage guidance. The key 'after' relationship is front-loaded, and every sentence earns its place.

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

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

For a tool with a nested selector object, multiple parameters, and an output schema, the description covers the core concept, the statistical test, and the intended usage context. It does not explicitly detail the two selector sources or parameter specifics, but those are fully described in the schema. The reference to using it after regimen_evaluate_track_record provides the prerequisite context, making it adequately complete.

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

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

The schema description coverage is 100%, so each parameter (detail, maxDates, selector, minSample) already has a detailed description. The tool description adds no additional parameter-level meaning; it focuses on the overall purpose and methodology. Since the schema carries the full burden, the baseline of 3 is appropriate.

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

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

The description states a specific verb ('Break a strategy’s returns down') with a clear resource (market conditions per date) and output (performance per bucket). It also distinguishes itself from the sibling regimen_evaluate_track_record by positioning itself as the follow-up that reveals where an edge comes from, which differentiates its purpose.

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

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

The description explicitly says to use this tool after regimen_evaluate_track_record when you need to know WHERE an edge comes from or whether it is a bet on conditions that could end. It gives a clear trigger condition but does not explicitly mention when not to use it or name alternative siblings like regimen_describe_factors or regimen_self_attack, so it falls just short of full exclusion guidance.

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