whoami

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

No annotations are provided, so the description carries the full burden. It discloses the output contents (name, email, member since) and implicitly indicates a read-only operation via 'Show.' While it does not discuss potential errors or authentication requirements, the simplicity of a whoami tool makes the behavior transparent enough.

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 compact (two sentences) and front-loaded with the core action. The first sentence states the purpose and output; the second adds usage context. Every word earns its place with no 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?

For a zero-parameter tool with no output schema, the description fully covers what the tool does, what it returns, and when to use it. It is complete within the context of its simplicity and sibling differentiation.

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 the schema trivially covers everything. The baseline for 0 params is 4, and the description adds semantic value by explaining what information will be returned for the session, making the purpose even clearer.

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 tool's purpose: 'Show which wealthAPI user this session is acting as (name, email, member since).' The verb 'Show' is specific, and the resource 'wealthAPI user' is well-defined. It naturally distinguishes from sibling tools like list_accounts, which focus on account data rather than session identity.

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 says 'Use this to ground yourself or when the user asks 'which account is this?',' providing clear context for when to invoke the tool. However, it does not mention when not to use it or name alternative tools for related but distinct tasks, stopping short of full 'when/when-not/alternatives' guidance.

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