brief

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

Annotations already declare readOnlyHint=true, so no mutation warning is needed. The description adds useful cost/behavior context ('Cheaper', 'one-line') and a scope prerequisite, but does not disclose deeper behavior such as caching, data loading, or failure modes, which matters given the tool can also accept data_path and result_id.

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 two sentences with no filler. It front-loads what the tool does, then adds the key comparative guidance about cost and alternative. Every sentence serves a distinct purpose.

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?

The description is adequate for a tool with rich parameter schemas and an output schema, but it leaves ambiguity around what 'result object in scope' means operationally and how an agent should invoke the tool to access that object. The contrast with brief_result helps, but the core prerequisite is not fully specified.

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?

Schema description coverage is 83%, so the parameter documentation already carries most of the burden. The description adds little about parameters, mainly the 'result object in scope' context, which is not directly mapped to any schema property. This is a typical baseline where the schema already explains parameters adequately.

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 clearly states the tool produces a 'one-line agent-friendly brief for a fitted result' and explicitly contrasts it with the sibling 'brief_result', including the condition that selects between them. This is enough for an agent to understand the tool's role and distinguish it from related tools.

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 names the alternative 'brief_result' and gives a concrete condition: use this tool when you already have the result object in scope because it is cheaper. It implies the alternative for other cases, but does not explicitly spell out when not to use it, so it is clear but slightly implicit.

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