update-body-measurement

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

Adds context beyond annotations: the API doesn't support clearing fields, so null values are omitted. This explains the idempotent behavior (sending same fields multiple times yields same result) and potential destructive nature (updating fields). The 404 response is also disclosed.

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 concise, with three sentences that cover purpose, behavior, and caveats. No unnecessary words or repetition. Well-structured and easy to parse.

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?

Given 18 parameters and no output schema, the description covers the essential behavioral aspects: partial update semantics, null handling, required date, and 404 error. Missing success response format, but this is acceptable without an output schema. Adequate for agent decision-making.

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 coverage is 100%, so every parameter is described. The description adds valuable overall behavior: only provided fields are sent and updated, and at least one measurement field must be provided (not enforced in schema beyond date). This clarifies how to construct requests correctly.

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 it updates an existing body measurement entry for a given date, specifying the resource and action. It implicitly distinguishes from sibling tools like create-body-measurement by emphasizing 'existing' but does not explicitly contrast.

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?

Provides clear guidance: null values are treated as omitted (cannot clear fields), requires at least one measurement field, and returns 404 if date doesn't exist. This tells the agent how to use the tool correctly and what to expect.

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