lookup_ideal_weight

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

With no annotations, the description carries the full burden. It discloses the BCS-conditional scope (4–5/9) and a required output-discipline behavior (cite sourceUrl, caveat that BCS matters more than scale). However, it says nothing about what the tool returns (range format, source availability) or failure behavior for unknown breeds.

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 short sentences, front-loaded with the core action. The citation/BCS reminder is arguably guidance rather than description, but it earns its place given the medical-adjacent nature of the tool.

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 2-param lookup with no output schema and no annotations, the description covers scope and caveats reasonably but omits return shape and error handling (unknown breed). Adequate but with clear gaps.

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 coverage is 50% – breed has a description with format examples, species only has an enum. The description adds the 'Domestic Shorthair' fallback convention, which is useful, but doesn't clarify slug vs. display-name handling for breed.

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 (look up) and resource (ideal adult weight ranges for cat/dog breeds at a stated BCS), with units included. It is clearly distinguishable from siblings like convert_cup_to_grams and calculate_pet_calories.

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?

Gives a concrete usage hint ('Use Domestic Shorthair for typical house cats') and a downstream instruction to cite sourceUrl. It doesn't explicitly state when NOT to use it vs. list_supported_breeds, but the context is clear enough.

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