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

With no annotations, the description carries the weight and does so well: it discloses the one-time return of a merchant API key, mandates storing it in a secret manager, and forbids logging the result. Missing are idempotency/irreversibility semantics (whether a consumed challenge blocks retry, whether enrollment can be repeated).

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, ordered by importance: what it does, the security constraint, then the handling obligation for the returned secret. No 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 4-required-param mutation with no annotations and no output schema, the description covers the security-critical behavior and the return shape (one-time API key). Gaps are the undocumented 'name' parameter and error/retry behavior.

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 0%, so the description must compensate. It clarifies the meaning of wallet, signature, and challengeId through the EIP-191/message-from-challenge framing, but the required 'name' parameter (merchant name, with a pattern and length limits) is never mentioned.

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 ('Complete merchant enrollment') and pins the mechanism: an EIP-191 signature over the exact message from create_merchant_enrollment_challenge. That also separates it from the sibling complete_merchant_enrollment_transaction, which follows a different completion path.

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?

The prerequisite chain is explicit — the signature must come from create_merchant_enrollment_challenge and must be a wallet signature, never a private key. It does not, however, explicitly rule in/out the transaction-based sibling or state what to do if the challenge has expired.

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