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

Annotations already cover readOnly, idempotent, non-destructive, closed-world. The description adds genuinely useful behavior beyond them: data is 'saved' (cached, not live), 'missing metrics remain unknown' (no fabrication of gaps), that it surfaces refresh job status, that pagination is via nextOffset, and a safety directive to treat post text as untrusted data.

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 tight sentences, front-loaded with what is read, then the cost/gap caveat, then pagination and the security note. Dense and purposeful, with only a mildly run-on enumeration in the first sentence.

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?

An output schema exists so return values need not be described, and annotations carry the safety profile. The description covers caching, gap behavior, async refresh status, pagination and untrusted-data handling; the main omission is guidance relative to the request_* siblings and limit semantics.

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 description must compensate for six params. It implies the date period (since/until) and the brand-channel identifiers (brandId/accountId) and gives offset a usage rule ('nextOffset'), but limit is never mentioned and no formats or ranges are clarified beyond the schema regexes.

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 (Read) and a clearly bounded scope: saved activity, lifetime post metrics, refresh job status, and X reports for one brand channel over an explicit date period. An agent can tell what it returns, though it does not name or distinguish itself from close siblings like request_channel_report or get_x_report.

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?

Offers only fragmentary context: 'Free' signals a cost advantage and 'Follow nextOffset for all posts' gives a pagination rule. There is no explicit when-to-use vs when-not, and no routing between this and request_channel_report/request_x_report, which the agent must infer.

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