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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds the specific conversion formula and the fact that it returns both the human-equivalent age and life stage, which is useful behavioral context beyond the annotations. It doesn't mention edge cases like age 0 or 40, but the schema already constrains those.

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 sentences with no filler. The core action and formula are front-loaded, and the source URL is appended without disrupting the main content. 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?

The description is complete for a simple, single-parameter, read-only calculator. It explains the conversion method and return values. The output schema exists, so return values are further documented. The only minor gap is not explicitly stating the life stage categories, but that's not necessary for calling the tool correctly.

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 fully documents the catAge parameter (type, range, description). The description adds the conversion chart context but doesn't add new parameter-level semantics beyond what the schema provides. Baseline 3 is appropriate.

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 tool converts a cat's age in years to an approximate human age, specifies the exact conversion chart (15, 24, then 4 a year), and mentions the return values (human-equivalent age and life stage). This distinguishes it from the sibling hopi_dog_age_calculator and hopi_age_calculator.

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 when to use it: when you need to convert a cat's age to human years. It doesn't explicitly state when not to use it or name alternatives like hopi_dog_age_calculator, but the specificity of 'cat' and the conversion chart makes the usage context clear. A small gap is not mentioning that this is for cats only, not dogs or other pets.

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