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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), so the description's added value is real: default ordering (oldest first), the per-post `timezone` convention for rendering times, and the hint that re-reading is how you observe an image landing (async image generation). That is meaningful behavior not present in the structured fields.

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?

Three compact sentences, front-loaded with what is returned and in what order, then filters. The parenthetical 'read it again to see an image land' is informal but carries real information, so it earns its place.

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?

No output schema exists, and the description compensates by enumerating returned fields, ordering, and timezone rendering. A mutation-free read tool with full schema coverage needs little more; only error/empty-state behavior is unaddressed.

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 description coverage is 100%, so the three filters are already documented with format and intent. The description paraphrases them (task_id = one post in full; plan_id/social_group_id = filters) without adding syntax, precedence, or combination rules, so it sits at the baseline.

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 resource and scope: AI Planner posts still awaiting review, with the fields returned (captions, image scenes, images, times). This implicitly separates it from list_posts and get_post, though it never names a sibling outright.

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?

'Give task_id for one post in full' and 'Filter by plan_id or social_group_id' explain how to narrow results, but the agent is left to infer when this tool beats list_posts or get_post. No explicit exclusions or alternatives are given.

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