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

In addition to the annotations (readOnly, idempotent, non-destructive), the description adds the 'visible' scope and a specific pagination contract: layering on next_offset until has_more is false. These are useful behavioral details beyond the annotations, even though sorting and return format are not described.

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?

Two sentences carry all essential information: purpose first, then the pagination rule. There is no fluff, redundancy, or verbose preamble.

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?

Combined with the rich schema, the description gives enough context for an agent to list posts and paginate correctly. 'Visible' is not fully defined and the return shape is not explicit, but for a read-only list tool with no output schema, these are moderate gaps covered by the pagination note and 'posts' wording.

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 covers all seven parameters with descriptions, including defaults and allowed values, so schema coverage is 100%. The tool description does not need to add parameter-level semantics; it also mentions next_offset/has_more, but those are response fields, not input parameters.

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 identifies the action ('lists') and the resource ('visible posts') and mentions filters and pagination. It is distinct from sibling list tools by focusing on posts, though it does not explicitly compare itself with invoke_get_post or other list 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?

The description provides pagination instructions but does not state when to use this tool versus alternatives like invoke_get_post or invoke_list_campaigns. There are no exclusions, alternative conditions, or explicit context selection cues beyond the generic phrase 'Lists visible posts'.

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