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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), and the description adds substantive context beyond them: the source networks read (Bluesky, Mastodon, Facebook, Instagram with views), the 30-day post-publication read window, and critically that X, LinkedIn, Threads, TikTok and YouTube return available: false and must never be compared on these numbers. That is a behavioral constraint an agent could not infer from schema or annotations.

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?

The content is appropriately sized and front-loaded — return contents first, then use cases, then data-source caveats. It is a single dense paragraph with a semicolon-chained clause list that could be slightly tightened, but every clause carries information the agent needs.

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?

No output schema exists, so the description carries the return-value burden and does so by enumerating the metric groups and the best-posts list. Combined with the source-network caveat and the sibling routing, an agent has everything needed to call it and interpret the result correctly.

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%: `from` and `to` document their defaults (now / 30 days before `to`) and `top` documents its by-interactions semantics and default of 5. The description restates the 30-day default period but adds no syntax or format detail beyond the schema, so the 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?

The description names a specific resource (published post performance) and enumerates exactly what is returned: totals, per-network numbers (posts, views, likes, comments, shares, followers and their change), interactions per publication day, and best posts. It explicitly distinguishes itself from the sibling get_post, so an agent can route correctly without opening either schema.

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?

It states concrete triggers — 'when the user asks what worked, which network or which post performed best, or to pick the next posts' topics and times' — and names the alternative with its selecting condition: 'use get_post instead for one post's numbers'. Both the when and the when-not are explicit.

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