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

Annotations already declare readOnly/non-destructive/closed-world, so the lower bar applies; the description still adds real behavior: the 62-day maximum window for calendar and the fact that returned descriptions are truncated. It does not explain result ordering or how many items history returns, so it is not fully transparent.

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, front-loaded with what it lists and the mode split, then the truncation caveat and the escalation path to get_post. No redundant restatement and nothing that could be cut without losing information.

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 an output schema present, return-shape explanation is unnecessary, and the description covers modes, the date-range constraint, and truncation. It leaves unanswered how many items history/scheduled return and whether results are ordered, which matters for a list tool but is a minor gap.

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 baseline is 3; the description nonetheless adds semantics beyond the schema by tying from/to to the calendar view only and imposing a 62-day cap that appears nowhere in the parameter definitions, plus noting 'fallido' as a history outcome the schema enum text omits.

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 (list) and resource (posts of a brand) and enumerates the three concrete modes (history/scheduled/calendar), which lets an agent distinguish it from get_post, compare_posts or get_post_stats without opening schemas.

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?

Explicitly routes the agent: use calendar with from/to for range queries, and use get_post when full text or per-network copy is needed. Missing only an explicit statement of when *not* to use it (e.g., single-post lookups or aggregate stats), which the sibling set makes relevant.

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