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

Annotations already establish this as a safe read (readOnlyHint) over external data (openWorldHint). The description adds useful payload context (TikTok returns views/shares/reach, YouTube returns views), but discloses nothing about ordering, recency window, pagination, or result limits.

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, and the core purpose plus the platform-specific return fields are front-loaded. The trailing filter advice is compact and 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?

There is no output schema, so the description carries the return-value burden and does partially address it via engagement fields. But with 0% schema coverage and an unexplained profileId plus no pagination or 'recent' definition, an agent lacks enough to call this reliably.

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 0%, so the burden falls on the description. It explains platform and accountId as narrowing filters, but profileId is never mentioned, leaving one of three parameters entirely undocumented in both schema and description.

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) with the platforms covered and the engagement data returned. It is clearly distinguishable from siblings like list_comments or get_instagram_insights. It stops short of a full sibling differentiation statement, so a 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?

Gives one concrete usage tip — filter by platform or accountId to keep the response small — which implies when to use the filters. However, it gives no guidance on when to prefer this tool over siblings such as list_comments or the per-platform insights tools, and no mention of the profileId parameter's role.

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