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

Annotations already declare readOnly/idempotent/non-destructive, and the description adds genuine extra context: results are statistical benchmarks rather than quotes or policy recommendations, U.S.-average pricing, and widget-rendering behavior that should shorten the text reply. It does not describe pagination or response structure, but for a read-only comparison tool the disclosure is solid.

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?

Use case and scope are front-loaded and most sentences carry unique information. Minor redundancy between 'asks X or Y' and the later 'Use for X vs Y questions', and the nested parenthetical on insurance premiums is dense, but overall efficiently written.

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 no output schema, the description correctly compensates by enumerating the compared attributes and the cost outputs (lifetime cost, modeled monthly premium at age 1), and it front-loads caveats and downstream reply behavior. An agent has everything needed to call and frame 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?

A single parameter at 100% schema description coverage, so the schema already documents it. The description corroborates the 2–3 breed constraint but adds no name-format or disambiguation guidance beyond what the schema provides, matching the baseline of 3.

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 (compares) and resource (2–3 dog breeds) and enumerates the exact comparison dimensions, so an agent can distinguish it from assess_breed_fit or get_breed_profile without opening the schema.

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?

Explicitly names triggering phrasings ('X or Y', 'X vs Y') and multiple exclusions: symptoms/emergencies/treatment (refer to vet), training and behavior how-tos, and non-U.S. cost questions. This is a full when/when-not statement.

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