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

No annotations are provided, so the description carries the full burden. It does not clarify whether this is a read-only lookup or a mutating/enriching operation, and it omits any mention of external data sources, auth requirements, costs, or rate limits. The caveat 'when available' adds some transparency but is not sufficient for a no-annotation tool.

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?

A single, front-loaded sentence with no filler. It states the verb, target, output fields, and availability caveat efficiently, earning its place entirely.

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 one-parameter tool with no output schema, the description covers the key outcome: profile data including name, phone, company, position, and LinkedIn/X profiles, with a 'when available' caveat. It is largely complete for a simple enrichment lookup, though it could mention return format or failure behavior explicitly.

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 input schema documents the only parameter with 100% coverage, so the baseline is 3. The description's 'known email address' phrasing adds minor context but no format, validation, or syntax details beyond what the schema already provides.

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 action and resource: 'Enriches a known email address with associated profile data'. The phrase 'known email address' helps distinguish this from sibling tools like run_email_finder and run_email_validation, though it does not explicitly name alternatives.

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 clear context: use this tool when you already have an email address and want associated profile data. It does not list exclusions or explicitly name when to prefer a sibling, but the 'known email address' framing is enough to convey the primary use case.

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