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

With no annotations provided, the description carries the full burden of behavioral disclosure, and it does provide crucial context: it reveals that authentication is required and implies a session dependency. However, it does not describe the exact return format or error behavior (e.g., what happens if not authenticated). The description starts to cover behavioral traits but is not exhaustive, so a 3 is appropriate.

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 two sentences, front-loaded with the core purpose, then immediately addressing the access requirement. Every word earns its place; there is no fluff. It efficiently communicates both function and usage-critical constraints.

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 tool is simple (no params, no output schema), so the description is nearly complete: it states what it returns and how to authenticate. It lacks explicit detail on the return schema, but with no output schema, the agent might appreciate a hint about the structure; however, the description of 'account details, plan, and settings' is sufficient for a basic understanding. Minor gap, hence 4.

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 tool has zero parameters, so parameter semantics are N/A. The baseline for 0 parameters is 4, and since the description provides context about what the tool returns and its preconditions, it contributes meaningfully beyond the schema. There is no schema coverage issue; the description adds value by explaining the tool's purpose and access requirements.

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 clearly states the verb ('Get') and the resource ('current authenticated user'), and explicitly lists what it returns (account details, plan, settings). It is distinct from siblings like get_my_profile and get_verified_user by focusing on the API key owner rather than a profile or another user. No ambiguity remains about what the tool does.

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 explicitly states the prerequisite (needs a Proof account) and provides specific authentication steps, including naming the alternative tool (start_login) and describing the session flow. It tells the agent exactly when to use this tool (after authentication) and what to do if not authenticated (sign in with start_login, then call again). This is exemplary guidance.

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