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

Goes well beyond the annotations by disclosing the 3-credit cost, the refund policy when no email is found, and that results are 'verified live' — critical context for a non-idempotent, open-world lookup. It also preempts output-shape questions by naming role and company alongside the email.

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 carrying purpose, routing, cost, and refund policy with zero filler; the core action leads the first sentence and the alternative follows immediately.

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?

With no output schema, the description still tells the agent what comes back (email, role, company) and what happens on failure (refund). Nothing an agent needs to call it correctly or explain the cost to a user is missing.

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?

Only one required parameter at 100% schema coverage, and the schema already supplies the format and an example URL. The description reinforces that the input is a profile URL specifically but adds no syntax beyond the schema.

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?

States a specific verb and resource ('Given a LinkedIn profile URL, return that person's professional email address') plus the returned extras (current role and company), and explicitly names the sibling it is not: find_work_email.

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?

Gives the exact selection condition ('when you have someone's LinkedIn page and need to email them') and names the alternative with its own condition ('for a name and company without a URL use find_work_email'), leaving nothing to inference.

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