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

Annotations already communicate read-only, idempotent, and closed-world. The description adds useful behavior beyond that: it returns full provenanced records and a notFound list for unknown slugs. This is meaningful behavioral context without contradicting the 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?

Two sentences, front-loaded with purpose and examples, then completion of return behavior and section guidance. There is no fluff or repetition of schema details; 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?

Despite having no output schema, the description states the return shape (full provenanced records plus notFound list) and covers the essential input semantics for both parameters. The default section and minItems are left to the schema, which is acceptable because they are present there.

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%, with only 'section' described in the schema. The description compensates by explaining that slugs are vendor slugs, giving concrete examples, and linking section to list_sections. It fills the main semantic gap for both parameters.

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 states a specific verb ('Compare'), exact resource ('vendors'), and the selection mechanism ('by slug within any theme'), with concrete examples for two different themes. It is immediately distinguishable from siblings like search_vendors or compare_products.

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?

It gives a clear use-case: when you have specific vendor slugs and want side-by-side comparison in a theme. It also instructs where to get valid section slugs (list_sections). It does not explicitly name alternative tools to prefer in other cases, so it misses a 5.

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