whoami

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. It states the return value (identity or 'managed=false'), which implies a read-only operation, but it does not explicitly mention that it has no side effects, requires no permissions, or cannot fail. For a simple identity query, this is acceptable but not exhaustive.

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, compact sentence that front-loads the core function ('Return the managed agent identity') and immediately clarifies the edge case. Every word contributes value, with no redundant phrasing or filler.

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 specifies what the tool does and what it returns. It covers both the managed and unmanaged cases, leaving nothing missing for an agent to call it correctly. The simplicity of the tool means no further context is needed.

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 fully covers everything (coverage 100% trivially). Per calibration, a baseline of 4 applies since there are no parameters to document. The description adds no parameter-specific meaning because none exist, which 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 clearly states the tool's purpose: returns the managed agent identity inherited by the MCP process, with a fallback for external hosts. It uses a specific verb ('Return') and resource ('managed agent identity'), leaving no ambiguity about what it does. This distinguishes it from sibling tools like 'status' or 'list', which handle other concerns.

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 use when you need to know the managed agent identity or whether the host is managed. However, it does not explicitly mention alternatives or when not to use it. Sibling tools like 'doctor' or 'status' might cover similar diagnostics, but no exclusions or comparative guidance is provided, keeping this at a basic clear-context level.

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