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

Annotations (readOnlyHint=false, destructiveHint=false) indicate a mutation but not destructive. The description adds context about business permission checks and grace periods, which informs the agent about prerequisites and potential blocking conditions. However, it does not detail what happens upon success or side effects beyond the confirmation, so not a perfect 5.

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 four tightly written sentences, each adding essential information. The purpose is front-loaded, followed by clear usage instructions. No redundant or extraneous text.

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?

Given the tool has multiple parameters and no output schema, the description is incomplete. It covers usage guidelines well but omits parameter details and return behavior. The agent lacks information on what the output or side effects of a successful confirmation are. This is a significant gap despite the strong guidelines.

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?

The input schema has 5 parameters with 0% description coverage. The description does not explain any parameter meanings, types, or relationships. While the usage guidelines are helpful, the agent is left to infer parameter semantics solely from the schema, which lacks descriptions. The description fails to compensate for the low schema coverage.

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 clearly states the tool confirms a signed custom-domain signup payment for a managed community. The verb 'Confirm' and resource 'custom-domain signup payment' are specific, and the scope 'for a managed community' distinguishes it from sibling tools like 'verify_custom_domain_payment' and 'create_custom_domain_signup'.

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 description explicitly tells when to use this tool (after checking business permissions and calling check_business_tool_access) and when not to (FREE businesses cannot use it). It also provides step-by-step instructions: check permissions, show grace-period warning and resubscribe link, never proceed if access is blocked. This is exemplary guidance.

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