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

Annotations declare readOnlyHint=true and destructiveHint=false, and the description does not contradict these. It adds valuable behavioral context beyond annotations, such as the need for permission checks, the restriction for FREE businesses, and the dependency on check_business_tool_access. This helps the agent understand the access control and side-effect profile.

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 4 sentences long, front-loaded with the purpose. While it provides necessary instructions, it is somewhat verbose (e.g., explaining interchangeability of 'business' and 'community'). Some redundancy could be trimmed without losing clarity.

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 access control context well but does not explain what the tool returns (no output schema) or the meaning of each parameter. For a tool with 4 parameters and no output schema, this leaves gaps in completeness, though the preconditions are thoroughly addressed.

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 4 parameters with 0% description coverage. The description fails to explain any of them individually, only mentioning 'mail type' in the purpose. It does not clarify what 'default', 'mailCourseOffer', or 'communityId' represent, nor their formats or constraints. Given the low coverage, this is a significant gap.

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 'Get community mail content for a mail type', using a specific verb and resource. It distinguishes from sibling tools like send_business_mail, update_community_mail by focusing on retrieval. However, it could be more specific about what 'content' includes (e.g., subject, body, attachments).

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 instructions on when to use this tool: check business permissions, call check_business_tool_access before collecting inputs, show grace-period warning and verified resubscribe link, and never proceed when access is blocked. It also notes that FREE businesses cannot use it. This is comprehensive guidance that clearly separates this tool from alternatives.

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