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

Annotations already declare read-only, idempotent, non-destructive, closed-world, so the description does not need to restate safety. It adds real behavioral context: optional parameters silently default to neutral, values must never be guessed or assumed, and widget-displaying apps render a card so the agent should keep its text reply short and not restate the numbers. It does not say what happens with an unrecognized breed name or slug, which is the remaining relevant gap.

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?

Information-dense and front-loaded, with the purpose, the sample user phrasings, and the routing rule to match_dog_breeds all stated early. It loses a point for restating the usage trigger in overlapping forms ('Use this when the user asks whether a specific breed is right for them' then 'Use when someone asks is a <breed> right for me?'), which is mild redundancy.

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?

There is no output schema, and the description compensates by enumerating the return contents in detail, plus the widget-rendering caveat and the input-completeness rule. For an 11-parameter, enum-heavy scoring tool, an agent has everything it needs to call it correctly and interpret the result.

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 baseline is 3, but the description adds meaning the schema lacks: it identifies the five key answers that must come from the user (home, activity, experience, kids, time alone) and states that every other parameter defaults to neutral rather than failing. That materially changes how an agent should populate the 11-param payload.

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 precise verb+resource ('check how well one specific dog breed fits a person', 'computes a personal fit score and rank for that breed') and enumerates the concrete outputs (fit %, rank among 121 breeds, per-area breakdown, biggest mismatch, highest-leverage change). It differentiates cleanly from siblings by naming match_dog_breeds as the multi-breed alternative.

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 explicit triggers ('is a <breed> right for me?'), an explicit alternative ('Use match_dog_breeds instead when no breed is named'), and explicit exclusions (symptoms/emergencies/treatment -> vet; training and behavior how-tos). The requirement to collect the five key answers before calling, and to batch the request, is spelled out.

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