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

Goes well beyond the annotations by disclosing that the public key is temporarily stored, that the challenge is ten-minute single-use, and that it does not remove the existing record. The 'Never send a private key' warning is valuable security context. It stops short of describing how the challenge is subsequently consumed.

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?

Three short sentences, front-loaded with the action, then scope, then the critical security constraint. No wasted words.

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 mutation tool with no output schema, the description covers TTL, single-use behavior, ephemeral storage, and non-destructiveness. It omits the linkage to complete_signed_withdrawal for finishing the flow, which would fully close the loop.

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% and the publicKey format is fully documented in the schema, so the baseline is 3. The description adds the private-key warning, reinforcing the expected parameter semantics beyond 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 ('Start a signed withdrawal request') and implicitly contrasts with the completion sibling by using 'Start'. An agent can distinguish it from request_follow_challenge, though the description never names that sibling explicitly.

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?

Usage is implied: it starts a challenge that presumably must be completed with complete_signed_withdrawal, but the description never states that handoff or when to prefer this over request_follow_challenge. The 'does not remove the existing participation record' line does clarify scope, which helps.

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