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

The readOnlyHint annotation already covers the safety profile, so the description does not need to restate it. The description adds the concrete HTTP endpoint 'GET /users/{id}', which is useful, but discloses no additional behavior such as error handling, response shape, or auth requirements. This is acceptable for a simple read-only resource fetch.

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 tight sentence that states the operation, the scope, and the endpoint. There is no filler, and every part contributes to correct invocation.

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, read-only, simple fetch operation, the description is sufficient: it identifies the action, resource, and endpoint. It could go further by describing response format or not-found behavior, but these are minor gaps and no output schema exists to clarify them.

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 covers the single 'id' parameter at 100% coverage with its own description, so the baseline is 3. The description only restates 'by id' and adds no new semantic detail 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 explicitly states the action ('Get') and the resource ('a single user by id'), making the tool's purpose unambiguous. It naturally distinguishes itself from sibling list tools like portkey_list_users by emphasizing the singular scope.

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 phrase 'a single user by id' clearly establishes when to use this tool: when the agent has a specific user id and needs that one user, rather than a collection. It does not explicitly name alternatives or exclusions, but the context is clear enough for correct selection.

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