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

Annotations already mark the tool readOnlyHint=true and destructiveHint=false, and the description reinforces the read-only nature. It adds useful behavioral context beyond annotations: 'Free', data-quality flags, previous-period comparisons, and the caveat 'where available' for top posts, which helps set expectations for an open-world result.

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?

Three sentences with no filler; the core purpose is front-loaded and the content list is dense but efficient. The phrase 'evidence-shaped' is slightly vague, but overall every sentence carries meaningful 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?

There is no output schema, so the description carries the burden of explaining return content. It lists many relevant components, previous-period comparisons, deltas, breakdowns, series, and flags, which gives an agent a solid mental model of the response. It could mention failure modes or unsupported source combinations, but the description is still reasonably complete for a read-only analytics tool.

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 67%, with days and targetId already described; the source enum values are self-explanatory. The description maps 'connected Social Brand' and 'hosted managed account' to the source parameter, but adds little concrete parameter-level detail beyond what the schema already provides.

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 a well-defined resource: analytics snapshots for either a connected Social Brand or a hosted managed account. The scope is concrete enough to distinguish it from sibling post-listing and account-status tools, even without naming them.

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?

Explicitly tells the agent when to use it: before making performance claims or content recommendations. It does not spell out when not to use it or name an alternative, so it falls short of a 5, but the provided guidance is clear and actionable.

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