create-body-measurement

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

The description discloses that null values are treated as omitted (not clearing individual fields) and that a 409 is returned on duplicate date. These are important behavioral traits beyond the annotations (all false). No contradictions with annotations.

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, front-loading the main action. Every sentence provides necessary information without waste: creation, null handling, and conflict guidance.

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 aspects: unique constraint, optional fields, null handling, and alternative tool for updates. Minor gap: no mention of the success response (e.g., what is returned).

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?

With 100% schema description coverage, the baseline is 3. The description adds the context that all measurement fields are optional and that nulls are omitted, which is not explicitly stated in the schema descriptions for individual parameters. This adds value 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 the action ('Create'), the resource ('body measurement entry'), and the key constraint ('for a given date'). It also distinguishes from the sibling tool 'update-body-measurement' by mentioning the 409 conflict and suggesting its use instead.

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 tells the agent to use 'update-body-measurement' if an entry already exists (returns 409), which provides clear guidance on when not to use this tool. However, it does not elaborate on other usage scenarios or prerequisites.

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