find_email

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

With no annotations provided, the description carries the full burden. It discloses a caching side effect ('Cached in domain_facts on hit'), which is a useful behavioral trait. However, it does not mention rate limits (implied by 'via Hunter'), error behavior when no email exists, or whether the lookup is read-only. The caching note adds some transparency but not comprehensive disclosure.

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 extremely concise: two short sentences with no filler. It front-loads the core purpose and adds one behavioral note. Every word 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 single-parameter tool with no output schema, the description is adequate but not complete. It explains the main function and a caching side effect, but does not describe the return value structure, error cases, or when to use this instead of similar tools. Given the tool's simplicity, the description is minimally viable but leaves gaps.

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 schema has one parameter (domain) with no description, so schema coverage is 0%. The description only says 'for a domain', which adds little beyond the parameter name. It does not clarify expected format (e.g., with or without protocol), case sensitivity, or examples. The description fails to compensate for the lack of schema documentation.

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's purpose: look up a contact email for a domain via Hunter. It uses a specific verb ('look up'), names the resource ('contact email for a domain'), and identifies the external service ('via Hunter'). This distinguishes it from sibling tools like search_prospects or enrich_domain.

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?

No guidance is provided on when to use this tool versus alternatives. It does not mention any contrasting use cases, prerequisites, or excluded scenarios. The only additional context is the caching mention, which is not a usage guideline.

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