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

Annotations already declare readOnlyHint=true, so the read-only nature is clear. The description adds valuable context about permission requirements (check business permissions) and the need to verify access, but does not detail response format or potential side effects, which are not critical for a read operation.

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 front-loaded with the purpose and then provides a series of actionable instructions. Though slightly verbose (multiple imperative sentences), each sentence adds value for usage guidance. No redundancy with annotations.

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 4 parameters (0% schema coverage) and no output schema, the description should explain parameters and return structure. It covers usage constraints well but omits parameter semantics and any indication of the tool's output format, leaving critical gaps for correct invocation.

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 0% description coverage, and the description does not explain any parameter meanings. While communityId is implied as required, parameters like tlds, query, and isAiGenerated remain completely undefined, forcing the agent to guess their roles.

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 explicitly states 'Search available custom domains for a managed community', using a specific verb ('Search') and resource ('available custom domains'). This distinguishes it from sibling tools like list_business_custom_domains or delete_custom_domains, as it focuses on discovering domains not yet connected.

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 provides explicit prerequisites: check business permissions, call check_business_tool_access before collecting inputs, show grace-period warnings, and never proceed when access is blocked. It also states that FREE businesses cannot use this tool, offering clear when-to-use and when-not-to-use guidance.

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