list_vendors

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

With no annotations, the description carries the burden of disclosing behavior. It indicates a read-only operation ('List') and specifies the output details (family counts and URLs). It does not mention pagination or rate limits, but given zero parameters and a simple listing purpose, this is sufficient.

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 a single, concise sentence that immediately states the action and the expected output. It wastes no words and is front-loaded with the core purpose.

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?

Given the tool's simplicity (no parameters, no output schema), the description fully captures the necessary context: it tells the user exactly what the tool does and what it returns. There is no additional behavioral or return-format information that would be expected for such a straightforward listing operation.

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?

The tool has no parameters, so the schema description coverage is trivially 100%. The description adds value by explaining what the resulting list includes, which is helpful context for the user even though there are no parameters to document. Baseline for zero-param tools is 4.

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 clearly states a specific action ('List') on a specific resource ('all vendors') and includes what information is returned ('family counts and vendor page URLs'). It distinguishes itself from sibling tools like lookup_part and search_models, which perform targeted operations, while this is a comprehensive listing.

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 usage context is implied: use when you need a full list of vendors. However, there is no explicit guidance on when not to use it or how it compares to alternatives like bulk_check or get_family. The description lacks explicit exclusionary or alternative references.

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