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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is clear. The description adds context about permissions and the interchangeability of business/community, but lacks details about return format or pagination. With annotations present, the description provides marginal additional behavioral context.

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 five sentences long, each adding value. It starts with the core purpose, then provides usage guidelines and clarifications. While not extremely concise, it avoids redundancy and is structured logically.

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 simple list operation with 1 parameter and annotations present, the description covers purpose, permissions, and prerequisites. However, it does not mention return value structure, pagination, or error handling. With no output schema, the description could be more complete, but it is adequate for basic usage.

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 schema has 1 parameter (communityId) with no description (0% coverage). The description does not explain the parameter's meaning, format, or how to obtain its value. It briefly mentions 'community managed by the authenticated user,' but this does not clarify the parameter semantics. The description fails to compensate for the lack of schema documentation.

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 that the tool lists custom domains for a community managed by the authenticated user, and clarifies that business and community are interchangeable. However, it does not differentiate itself from the sibling tool 'list_community_custom_domains', which may be confusing since they seem to overlap.

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 guidelines: check business permissions, note that FREE businesses cannot use this tool, call check_business_tool_access before collecting inputs, and show grace-period warnings. It gives clear prerequisites and steps, but does not mention alternative tools or when to prefer this over siblings.

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