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

The annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is known. The description adds meaningful behavioral context beyond annotations: it identifies the exact profile fields returned and states that only authenticated basic access is required, with no business OAuth scope. This helps the agent understand auth requirements that annotations do not cover.

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, front-loaded with the return value and followed by the authentication context. Every sentence adds useful information, with no repetition of the schema or annotations.

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?

The output schema handles the return shape, annotations cover the safety profile, and the description supplies the remaining critical context: the returned fields and the authentication requirement. For a zero-parameter read-only profile tool, nothing essential 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?

There are zero parameters, and schema coverage is 100%, so no parameter semantics need explanation. The description does not invent or misdescribe parameters. Baseline for a zero-parameter tool is 4.

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 verb and resource (returns the current user's profile details) and enumerates the exact fields returned. It is clear and concrete, though it does not explicitly differentiate itself from siblings—largely because no sibling is similarly named or scoped.

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 implied by the tool's name and the description's field list, but there is no explicit guidance on when to call it versus alternatives. It does not state prerequisites beyond authentication or exclusion conditions, leaving the agent to infer that this is the canonical way to retrieve the current user's profile.

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