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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds genuinely non-annotated context: what comes back (contact details) and that the email is conditional ('when available'), which matters for a lookup with no output schema.

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 sentence with the input requirement and the return content front-loaded; no filler or redundancy.

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 one fully-documented parameter and no output schema, the description's statement of what is returned (contact details, email when available) covers the main missing piece. It stops short of describing fallback behavior when no email is found, keeping it just under a 5.

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 coverage is 100% and the only parameter is fully documented with an example URL. The description's phrase 'full profile URL' reinforces that the value must be a URL rather than a handle, but adds little beyond the schema — baseline 3.

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 concrete verb and resource: looks up a LinkedIn profile by full profile URL and returns contact details. This clearly distinguishes it from siblings like run_linkedin_company_search or run_linkedin_domain, though it never names an alternative outright.

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?

Usage is only implied: the required 'username' being a full profile URL signals the lookup context, but the description gives no explicit when-to-use, when-not-to-use, or sibling routing (e.g., vs. run_linkedin_people_search).

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