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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description usefully adds a default behavior (omitting videoIds returns the most recent posts) and the 20-post cap, but says nothing about pagination, rate limits, or response shape beyond the metric list.

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 tight sentences with no filler; the returned metrics are front-loaded and the videoIds usage note follows immediately. Every clause carries 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 no output schema, the description carries the burden of explaining returns and does so by enumerating the metric families. Combined with the readOnly/openWorld annotations and full param descriptions, this is largely sufficient, though pagination and the behavior when more than 20 ids are supplied are 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 coverage is already 100%, so the baseline is 3, but the description earns credit by explaining that videoIds originates from list_posts and that omitting it changes the semantics to 'most recent posts' — behavior the schema does not capture. profileId is left to 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 verb (Return) and enumerates the exact metrics returned (watch time, full-watch rate, retention, impression sources, audience) for TikTok posts, which clearly separates it from get_tiktok_account_insights. It stops short of naming the sibling it differs from, so the differentiation is implied rather than stated.

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?

Provides real usage context: videoIds should come from list_posts and can be omitted to fall back to the most recent posts. However, it never says when to use this video-level tool versus get_tiktok_account_insights, get_tiktok_analytics, or get_youtube_video_insights, so the routing guidance is only partial.

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