whoami

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 main behavioral traits. The description adds value by specifying the exact information returned (tenant, role, plan), but this is not behavior beyond what annotations imply. The description does not contradict annotations.

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 short sentences with no filler. The main action is front-loaded ('Identifica o tenant, role e plano'), and the usage guidance follows directly. Every word earns its place.

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 tool with no parameters and no output schema, the description provides all necessary context: what it returns (tenant, role, plan) and when to use it. There is no missing information an agent would need to call it correctly.

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 coverage is trivially 100%. The description doesn't need to explain parameters. Baseline for 0 parameters is 4, and the description adds context about what it returns, but not parameter details (since there are none).

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 identifies the tool's purpose: it identifies the tenant, role, and plan of the current MCP session. The verb 'identifies' is specific, and the resource is well-defined. It distinguishes itself from all sibling tools by focusing on the current session context.

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 when to use it: 'Use para confirmar em qual organização e com qual nível de acesso você está conectado.' This gives a clear, actionable usage scenario. No alternatives are mentioned, but none are needed as it's a unique introspection tool.

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