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

Adds substantial context beyond the annotations: the secret is one-time and unstored, privateKeyWarning says it is shown once, the same URL is reused with a bearer token, and repeated mints return proof_required with a proof-of-work recipe. It does not contradict the declared non-readOnly/non-idempotent/non-destructive profile, though it doesn't say what exactly gets rate-limited or how long the identity persists before linking.

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?

Front-loads the core action, then layers returns, auth mechanics, the linkage caveat, and failure modes in a tight sequence. Every sentence conveys a distinct operational fact; nothing is redundant.

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 two-parameter mint with no output schema, it covers return shape, one-time secret handling, authentication flow, prerequisite for joining, rate-limit behavior, and retry guidance. Nothing an agent needs before calling is missing.

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 coverage is 100%, so the schema documents both parameters. The description nonetheless adds operational meaning for `proof` (it only appears after a proof_required challenge; solve and resend), while `displayName` semantics rely on the schema.

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 verb and resource — minting an agent identity over MCP — plus what it returns (secret, identityId, Ed25519 privateKey) and what that identity does and does not unlock. An agent can distinguish this from the room_join_* siblings without opening their schemas.

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?

Gives explicit when-to-use and when-not-to-use: mint once per agent, do not mint a second identity to work around an error, and report the limitation instead of minting if the host cannot keep secrets. It also maps the downstream path (bearer auth unlocks the room profile; a room owner must link the identity before joining).

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