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

With no annotations provided, the description carries the full burden. It states what the tool does and notes the email availability ('when available'), which is useful. However, it does not disclose any potential limitations such as authentication requirements, rate limits, or behavior when the profile is not found or the email is not present beyond the caveat. This is adequate for a simple read-only lookup but not rich.

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 a single, well-structured sentence that immediately states the action and result. It front-loads the essential information (lookup by URL) and includes the caveat about email availability without any wasted words.

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 simple, single-parameter tool, the description covers the essential return value (contact details, including email) and the input condition. It does not include an output schema, so the description's mention of the return content is important and present. There is no indication of missing critical information, though it could be more explicit about failure modes. The description is largely complete for the tool's simplicity.

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 already describes the sole parameter with a clear format and example (100% coverage). The description reinforces that the tool expects a full URL but adds no new semantic information beyond what the schema provides. Since coverage is high, the baseline of 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 uses a specific verb 'Looks up' and clearly identifies the resource (LinkedIn profile) and the outcome (returns contact details including an email). It distinguishes from sibling tools by specifying the input as a full profile URL, making it obvious when this tool is appropriate versus search-based tools.

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 implies the intended use case: when you have a complete LinkedIn profile URL and need contact details. It does not explicitly exclude other scenarios or name alternatives, but the clear condition ('by its full profile URL') provides enough context for an agent to select it correctly among siblings like 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.