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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds value by disclosing what the tool exposes (auth details, tenancy info) and explaining that it confirms attribution and tenancy, going beyond the hint annotations. It doesn't describe auth failure behavior, but for a whoami read tool that's acceptable.

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, zero filler. The first sentence enumerates the exact returned data, the second gives the actionable use case. 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, no-output-schema read tool with strong annotations (readOnly, idempotent, non-destructive), this description is complete. It fully covers what the tool returns and when to call it. There's nothing meaningful missing for an agent to confidently select and invoke it.

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?

Tool has 0 parameters, meeting the baseline of 4 for zero-parameter tools. There's no parameter burden to carry, and the description fully explains what the returned data represents, so no compensation for unknown params is needed.

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?

Description uses a specific verb ('Return') with clear resource scope: 'authenticated person or service agent, organization, workspace, role, and granted scopes.' The tool name 'handover.whoami' is distinctive and unrelated to any sibling, and the description clearly establishes it as an identity/auth verification tool, separating it from the surrounding data-management siblings.

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?

Description gives explicit when-to-use guidance: 'Call this before reading or publishing to confirm attribution and tenancy.' This provides clear actionable direction for the agent on when this tool should be invoked in a workflow, which is strong contextual framing.

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