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

Annotations already declare readOnly, idempotent, and non-destructive behavior. The description adds valuable context by stating it does not invent missing measurements and only works with 'exact public paddles', disclosing data fidelity expectations beyond the structured annotations.

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?

The description is two concise sentences that front-load the core action ('Compare...') and then state limitations. No redundant words or filler; every phrase 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?

For a simple read-only comparison tool with one parameter and no output schema, the description covers scope, limitations, and behavioral guarantees. It could optionally mention what fields are compared, but the current level is sufficient for an agent to select and invoke it 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?

With 0% schema description coverage, the description compensates by explaining 'slugs' as 'two to four exact public paddles', clarifying both the count constraint and the meaning of the parameter values. This adds significant semantic meaning beyond the raw 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?

The description uses the specific verb 'Compare' with a clear resource ('two to four exact public paddles') and explicitly states what it does NOT do (no personalized recommendation, no invented measurements). This distinguishes it from siblings like search_paddles and get_paddle.

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 phrase 'without generating a personalized recommendation' provides clear context for when not to use this tool, implying it is for direct comparisons rather than recommendations. However, it does not explicitly name alternative tools or provide exclusion criteria beyond the recommendation limitation.

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