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

Annotations already declare readOnlyHint, idempotentHint and non-destructive, so the safety profile is covered structurally. The description adds the return shape, which is useful, but no extra behavioral context (rounding, US M vs W handling, valid ranges) beyond 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?

Two short sentences, zero filler, with the core action front-loaded and the return shape plus a cross-reference trailing. Every clause 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?

With a 100%-covered 3-param schema, an output schema and full safety annotations, the description only needs to frame the operation, which it does. Restating the return object is mildly redundant given the output schema, but nothing an agent needs to invoke it correctly is missing.

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% with enums for both system parameters, so the schema already carries the parameter semantics; baseline 3 applies. The description's 'US (M/W)' gloss lightly reinforces the US_M/US_W enum split but adds no syntax or range 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?

States a specific verb (Convert) plus resource (shoe size) and enumerates the supported systems (EU, US M/W, UK), so an agent can tell it is a shoe-size converter. It does not, however, distinguish itself from the close siblings convert_shoe_size and calculate_shoe_size, whose purposes overlap heavily.

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 line 'See list_bundles for related "conversions" calculators' gives implied discovery context, but there is no explicit when-to-use or when-not-to-use guidance, and no routing against convert_shoe_size or calculate_shoe_size. Usage is only implied by the named scope.

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