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

Annotations already cover safety (readOnly, idempotent, non-destructive, closed-world), and the description adds real behavioral context beyond them: the 90-day aggregation window, workspace-timezone slotting, the 10-published-post data threshold, and the graceful 'it says so' fallback when data is insufficient. It does not say whether results are sorted or how many slots are returned.

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?

A single dense sentence that front-loads what is returned before the precondition. Nothing is wasted, though the clause about the 10-post minimum is tacked on and could be separated for readability.

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-value burden and does it well: it describes the shape (weekday + hour slots), the metric, the timezone, and the insufficient-data message. Only the ordering/length of the returned slot list is left unspecified.

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% and the single param is documented, so the baseline is 3; the description earns above that by explaining the omission semantics — without a platform you get overall results, with one you get per-platform results. That is genuine meaning beyond the schema's 'Only this platform'.

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+resource pair (returns weekday + hour slots ranked by average engagement) with the exact metric (likes + comments + shares) and time window (last 90 days). An agent knows precisely what it gets back. It does not distinguish itself from the adjacent sibling get_next_slots, which is the main clarity gap.

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?

Usage is implied rather than stated: the 90-day lookback and 'overall and per platform' framing suggest planning/best-time analysis, and the 10-post precondition tells the agent when the tool is meaningful. But there is no explicit when-to-use clause and no routing to alternatives such as get_next_slots or get_analytics.

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