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

With no annotations, the description carries the burden well: it discloses that the tool returns a message to sign with the agent wallet, that new authority requires a wallet signature, and that the challenge is bound to the intent to prevent replay across intents. It does not cover challenge expiry or the exact follow-up submission path, but the critical security behavior is explicit.

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 two dense sentences with the operational purpose front-loaded and the security rationale following immediately. Every clause adds useful selection or safety context without 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 one-parameter challenge tool with no output schema, the description covers the return value, the authorization requirement, and the intent-binding security property. It stops short of naming the next submission step explicitly, but it is otherwise sufficient for correct invocation.

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 0%, so the description must compensate. It explains the two intent semantics in business terms ('copy' to follow leaders, 'withdraw' to move funds) and ties them to the replay-protection behavior, though it uses shorthand rather than the exact enum values.

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 states a specific action: obtaining a message to sign as step 1 of gaining a new scope. It distinguishes the two scope intents ('copy' to follow leaders, 'withdraw' to move funds) and separates this from key rotation, which can only narrow scopes.

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?

It clearly frames usage as the first step for gaining new authority and explicitly notes that keys/rotate can only narrow scopes, which helps route the agent away from the wrong tool. It does not exhaustively name every sibling alternative, but the context is strong enough to select this tool correctly.

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