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

Annotations already indicate readOnlyHint=true and destructiveHint=false. The description adds context about business permissions and the restriction for FREE businesses, but these are more about usage conditions than behavioral traits like side effects or data modification. No contradictions with annotations.

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 somewhat verbose but every clause adds value. It front-loads the purpose and then details prerequisites. It could be trimmed slightly without losing meaning, but it remains clear and structured.

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?

The description covers prerequisites and restrictions well, which is good for a write operation (though annotations say readOnly). However, it lacks explanations of the parameters and what the tool returns (no output schema). Given the complexity (payment verification), more details about expected inputs and outputs would be beneficial.

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 defines two required parameters (signupId, communityId) with no descriptions. The tool description provides zero explanation of what these parameters represent (e.g., signupId from where? communityId for which community?). With 0% schema documentation coverage, the description should compensate but does not.

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's purpose: 'Verify a custom-domain signup payment for a managed community.' The verb 'verify' combined with the resource 'custom-domain signup payment' is specific and differentiates it from sibling tools like 'confirm_custom_domain_signup' or 'confirm_custom_domain_dns_records'.

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?

Explicit guidance is provided: 'Before offering this action or requesting its inputs, check business permissions. FREE businesses cannot use this tool... Call check_business_tool_access before collecting inputs. Show any grace-period warning and verified resubscribe link before continuing, and never proceed when access is blocked.' This tells exactly when and when not to use the tool, including prerequisites and alternative actions.

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