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

Annotations only mark this as a non-read-only, open-world, non-destructive write; the description goes much further, disclosing that business_key is returned exactly once, must be stored as a secret, and is the owner bearer credential for the REST API and /mcp/agents. It also states the operational limits (5 tries, 30 minutes), which the schema and annotations do not convey.

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?

Prerequisites come first, then the action and its one-time return value, then handling instructions, then limits. The telegraphic closing ('5 tries, 30 minutes.') is dense but fully readable given the preceding context.

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-param creation tool with no output schema, everything needed is present: inputs and their origins, the mutation performed, the returned credential, its one-time nature, and retry/expiry limits. No output schema exists, and the description still covers the shape of the critical return value.

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 carry the burden and it does: signup_id is the value returned from register_business, and code is the 6-digit value emailed to the business address. Both params are given provenance and shape beyond the bare string types.

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 ('creates the business') plus the key side effect ('returns business_key once'), and anchors it to the preceding step ('signup_id from register_business'), so it is unmistakable versus siblings like register_business or confirm_request.

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?

Explicitly names the precondition and trigger: it needs the signup_id produced by register_business plus the 6-digit code emailed to that address. An agent knows exactly when this tool is the right call and what must precede it.

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