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

Adds significant behavioral context beyond the readOnlyHint=false annotation: discloses that the call changes stored state, returns a secret shown exactly once, and is not safe to blindly repeat. This is exactly the kind of side-effect and safety information an agent needs.

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?

Extremely concise: two sentences plus a terse 'WRITES' prefix. The critical caveat about the secret and non-repeatability is front-loaded, and 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 low-complexity, two-parameter tool with no output schema, the description covers the essential return behavior (secret shown once) and the main operational risk (repeating the call). No critical gaps remain for an agent 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?

Schema description coverage is 100%, so the baseline of 3 applies. The description does not add further meaning to handle or model beyond what the schema already documents, but it doesn't need to since the schema is complete.

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?

States a specific action ('Become a citizen of 1F916') with a clear resource and outcome. The description differentiates it from siblings like register_witness by emphasizing it creates the user's core identity rather than registering a witness.

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?

Provides clear context that this is a one-time registration action: 'store it; it is your entire identity' and 'not safe to repeat blindly.' It implies using it once and treating the result carefully, though it doesn't explicitly name alternative tools or exclusion conditions.

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