get-body-measurement

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

No annotations are provided, so the description carries the transparency burden. It discloses that the tool returns all measurement fields for the date, which is useful. However, it does not mention error handling, permissions, or explicitly state that it is read-only (though the verb 'get' implies this). For a simple read operation, this is adequate but not rich.

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 concise sentences with no filler. It front-loads the action and then explains the return value, making it efficient 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?

For a simple single-parameter tool with no output schema, the description adequately states the purpose and return type ('all measurement fields'). It could benefit from mentioning the sibling tool for multiple measurements, but that is not essential for the tool's use. Overall, it is sufficiently 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 already fully documents the single 'date' parameter with its format and description, so the baseline is 3. The description's phrase 'by date' aligns with the parameter but adds no additional semantic detail beyond the schema.

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 'Get a single body measurement by date', which specifies the verb (get), resource (body measurement), and scope (single, by date). This distinguishes it from the sibling tool 'get-body-measurements' (plural) which presumably returns multiple measurements.

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 gives clear context: use this tool when you need a single body measurement for a specific date. It does not explicitly name alternatives or exclusions, but the word 'single' implies it is not for listing measurements, which is covered by the plural sibling.

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