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

Annotations already declare the tool read-only, idempotent, and non-destructive. The description adds useful behavioral context: output is a per-brand size plus any runs-small/runs-large note, and sizing is hip-based rather than dress-size-based. It does not cover edge cases like both parameters being provided, but that is minor given the annotation coverage.

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?

Three tight sentences front-load the core purpose, add necessary domain context, and state the return value without redundancy. Every sentence earns its place.

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 read-only lookup tool, the description covers what it does, the domain nuance, and the output shape. The main gap is that both schema parameters are optional, yet the description implies a measurement is required; it does not state that at least one must be supplied or what happens if neither is.

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 description coverage is 100%, so the schema already documents hip_cm and hip_inches in detail. The description only adds the general notion of a 'hip measurement' and does not clarify the relationship between the two optional parameters, such as whether one is required or how conflicts are resolved.

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 states a specific verb ('Find'), a clear resource ('period-underwear size in every brand'), and the required input ('one hip measurement'). It also reads distinctly from its siblings, which focus on absorbency and product finding.

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 provides clear context on when this tool is appropriate: when converting a hip measurement into period-underwear sizes across brands, especially because brands disagree. It does not explicitly mention when not to use it or name alternatives, but the usage context is unambiguous.

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