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

Annotations only mark it non-read-only, non-idempotent, non-destructive and open-world; the description adds the material consequences: the key is displayed once and must be stored, creation is gated on a wallet balance, and a hard cap of 3 keys per wallet. The error codes make the mutation's failure modes and side effects predictable.

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 tight sentences, front-loaded with the sequencing constraint, then the return shape, then preconditions and error codes. No filler, and each clause carries operational information.

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 write tool with no output schema, the description supplies the return object shape, the status code, the one-time-display caveat, and all failure conditions. An agent has everything needed to invoke it correctly and handle the response.

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 already documents all five parameters, including the optional `ref` and `label`. The description only reinforces `message`/`signature` provenance (already in the schema) and says nothing about `ref` or `label`, so it adds little beyond the structured fields — baseline 3.

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 (submit the signed message from trnch_register_message) and names the exact return payload `{ key, prefix, wallet }` plus status 201. It is unmistakably distinct from the sibling `trnch_register_message`, which it explicitly positions as the prior step.

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 an explicit ordering constraint ('Step 2 of 2'), the prerequisite balance (10 USDG or 0.004 ETH on Robinhood Chain), the failure routing (402 insufficient funds, 409 key cap of 3, 400 signature/message mismatch), and the alternative to use when no message exists yet. Nothing about when to call it is left to inference.

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