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

Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=false), so the bar is lower. The description still adds real behavioral context: results are paginated, and a null metrics field means no analytics collected, which is explicitly distinguished from a zero value. It does not describe pagination metadata or rate/limit behavior.

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?

Front-loaded with purpose, output shape, the required parameter, and the status vocabulary, then a second short paragraph for the metrics flag. No filler sentences; every clause conveys a distinct fact.

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?

With no output schema, the description carries the return-shape burden and does reasonably well: pagination, per-post metrics, and null-vs-zero semantics are covered. It omits pagination metadata (total pages/counts) and the general post field set, which an agent might want before relying on the response.

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 100%, so the schema baseline is 3. The description goes beyond it by enumerating the metric fields returned when includeMetrics is true (views, likes, comments, shares, engagement rate) and restating the status vocabulary as usable values, which adds practical meaning not spelled out in the schema.

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?

States a specific verb and resource ('List posts with filters') plus output shape ('Returns paginated results'), which distinguishes it from mutation siblings like create_post/delete_post. It does not explicitly name its closest sibling get_post, but 'instead of fetching them one at a time' implicitly draws the bulk-vs-single distinction.

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?

Gives a clear use case for includeMetrics ('compare how posts performed') and names the alternative pattern it replaces (fetching posts one at a time). It lacks explicit when-not guidance for the tool itself, e.g. when to prefer get_post for a single known post.

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