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

Annotations already declare readOnly, idempotent, non-destructive, open-world, so the safety profile is covered. The description adds useful scope beyond that by noting the posts are 'published' (excluding drafts/scheduled) and that metrics are returned. It omits ranking criteria (engagement measured how?), ordering, and any pagination or window behavior, so the added value is modest.

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 the resource and ranking criterion, followed by the rationale. No filler or redundancy, though the closing 'create more of what works' is mildly promotional rather than informational.

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 usefully enumerates the returned payload (captions, platforms, media type, metrics), which offsets the missing structured return definition. The remaining gap is what 'engagement' ranking actually means and how ties/ordering are handled.

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 days, limit, and platform are already fully documented with defaults and bounds; baseline 3 applies. The description mentions 'platforms' only as an output field and never clarifies the look-back window or result-count parameters, adding no meaning beyond 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 resource and ranking criterion ('best-performing published posts by engagement') and enumerates returned fields (captions, platforms, media type, metrics). An agent can distinguish it from list_posts (unranked) or get_top_performing_media (media, not posts). It stops short of explicitly naming those siblings, which keeps it at 4 rather than 5.

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?

'Study these to learn what content resonates and create more of what works' gives an implied intent and context of use, but there is no explicit when-to-use/when-not guidance and no routing against near neighbors like get_content_insights, get_analytics_overview, or get_top_performing_media.

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