update-body-measurement

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

Annotations indicate destructive and idempotent. Description adds critical details: partial update semantics, null handling, minimum field requirement, and 404 response. No contradictions.

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?

Four short, direct sentences. Front-loaded with purpose, then key constraints. No fluff.

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 mutation tool with 18 parameters, the description covers essential behavior, prerequisites, and error case. Could mention successful return value, but not mandatory given no output schema.

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 has 100% coverage with descriptions. The description adds value beyond schema: clarifies null meaning, imposes 'at least one measurement field' constraint, and explains partial update behavior.

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. The phrase 'existing' distinguishes it from create-body-measurement. It explains partial update behavior and prerequisites.

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 explicit guidance: only updates existing entries, requires at least one measurement field, nulls omitted, returns 404 if missing. Lacks explicit comparison to alternatives, but the sibling list suggests create-body-measurement for new entries.

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