Weight

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

Annotations already disclose read-only, idempotent, and non-destructive behavior. The description adds the selection logic (latest on/before date), but does not disclose behavior when the date parameter is omitted or when no entry exists, leaving some ambiguity. This is acceptable given annotation coverage but not richly transparent.

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?

A single, front-loaded sentence that efficiently conveys the tool's purpose without wasted words. It is appropriately sized for the tool's simplicity.

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?

With a simple one-parameter tool, an output schema, and robust annotations, the description covers the core behavior. However, the optionality of the date parameter and lack of edge-case handling (missing entries) leave a small gap that prevents full completeness.

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 0% schema description coverage, the description compensates by explaining that 'date' acts as a cutoff for selecting the latest entry. It adds meaning beyond the raw schema, though it omits the expected date format and optionality behavior, preventing a perfect score.

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 verb (Returns), the resource (weight entry), and the specific logic (latest on or before a date). This differentiates it from sibling tools like get_nutrition_trends or get_daily_summary, which handle broader or aggregated data.

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 implies usage for retrieving a single weight reading as of a date, but does not explicitly state when to prefer this over alternatives (e.g., get_nutrition_trends for trends) or provide exclusions. The agent must infer the appropriate context from the description alone.

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