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

Annotations declare readOnlyHint=true, which the description does not contradict. The description adds behavioral detail: 'Check exact contact details and ask about ambiguous matches' which implies that ambiguous results are possible and the agent should seek clarification. However, other behavioral aspects like pagination behavior or that 'get' requires a signer_id are covered by schema, so the description adds incremental value but not rich context. The description explicitly says to 'ask about ambiguous matches,' which goes beyond 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 concise, at about 30 words, and front-loads the main purpose. The first sentence states the core function, the second contrasts list/get, and the third gives usage advice. Each sentence earns its place, with no fluff.

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 simplicity (1 param, schema covers all) and no output schema, the description is quite complete. It tells the agent to check details and ask about ambiguity, which is essential for safe operation. The only minor gap is it doesn't explain what to do if the signer is not found, but that is inferred from 'ask about ambiguous matches.' Overall, it is sufficient for correct invocation.

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 all parameters are described in the schema. The description adds guidance on how to use the action parameter ('list searches the directory; get inspects a known signer'), which complements the schema. However, it does not add details on search/email filtering syntax (schema covers it), and it does not explain pagination beyond the schema. With high coverage, baseline 3 is appropriate.

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 the tool resolves a recipient to a workspace signer ID and distinguishes between 'list' (searches the directory) and 'get' (inspects a known signer). This is specific about the verb and resource, and makes a clear distinction from sibling tools like assinafy_save_signer, though it could explicitly name the sibling or contrast with broader search functions.

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 description provides a clear workflow: 'Check exact contact details and ask about ambiguous matches before sending invitations.' It implies usage when you need to resolve a recipient for signing, which is a distinct use case from other tools. However, it does not explicitly state when NOT to use it (e.g., when you only need to verify a document or find templates), but the context is adequate without exclusions.

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