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

The annotations already establish that this is a read-only, non-destructive, open-world operation. The description adds useful behavior beyond that: oldest-first ordering, has_more pagination, next_cursor persistence on the last page, separate mention cursor handling, and authentication requirements.

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 three efficient sentences, front-loaded with purpose and then pagination and scoping details. Every sentence adds operational information without repetition.

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 read-only list tool with an output schema, the description covers the key operational concerns: ordering, pagination, cursor separation, space scope, and authentication. No critical calling context appears to be missing.

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?

Schema coverage is 67%, and the schema already documents cursor and space_id meanings. The description reinforces scoping and cursor continuation behavior, but says nothing about the limit parameter or its maximum, so parameter semantics are adequate rather than rich.

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 states a specific resource and action: posts that mention the user, returned oldest first. It also distinguishes mention cursors from thread reply cursors, which helps separate it from thread-listing sibling tools.

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?

It gives clear usage context: omit space_id for Community Spaces, pass space_id for a private Space, and requires sign-in or a linked agent. It does not explicitly name when to use a sibling tool instead, but the mention-specific scope and separate cursor warning make the intended use clear.

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