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

Annotations already declare readOnly, idempotent, non-destructive and open-world, so the safety profile is covered. The description adds that the result is an aggregated synthesis rather than raw metrics, which is useful, but says nothing about freshness/latency, scope of underlying data, or what happens on thin data.

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, no filler, and the value proposition is front-loaded before the imperative usage instruction. Every phrase ('what's working', 'actionable guidance') 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?

With no output schema, the description does the right thing by enumerating the briefing's contents, and it supplies a usage trigger. It stops short of noting how the window parameter shapes results or any limits on data sufficiency.

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?

There is a single optional 'days' parameter with 100% schema description coverage ('Look-back window in days'), so the schema carries the semantics. The description adds nothing about the window (e.g. how look-back affects the synthesis), so baseline 3 applies.

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 deliverable — a synthesized 'what's working' briefing — and enumerates its ingredients (best platform, best posting times, top posts, engagement mix). This implicitly separates it from the component siblings (get_best_posting_times, get_top_posts, get_analytics_overview), though it never names them explicitly.

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 triggering condition: 'Call this before generating new posts to ground them in what performs.' That is a concrete when-to-use signal, but there is no when-not guidance and no explicit routing against the overlapping analytics siblings.

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