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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety and the open-web nature are covered. The description usefully adds that only data 'exposed on the Page's About tab' is returned (public-scope caveat), but says nothing about auth requirements, rate limits, or freshness/caching.

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?

Purpose is front-loaded and the field enumeration earns its length, but the sentence is a long run-on and the trailing 'id: Resource identifier.' is a verbatim restatement of the schema description that adds nothing.

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 an output schema present and annotations covering the safety profile, the description is complete enough: it covers accepted identifier formats and the shape of returned data. Only the routing rationale versus the dataset sibling is left implicit.

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 100% and the schema only says 'Resource identifier.' The description adds genuinely new information: the id accepts a page ID, a vanity name, or a full page URL, plus the contact fields keyed off that identifier.

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 gives a specific verb (fetches) and resource (a Facebook Page) and enumerates exactly what is returned: name, follower/like counts, intro, category, hours/price range, review count, and About-tab contact details. This is enough to distinguish it from dataset-style siblings without opening any 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 names one alternative (datasets_facebook_pages_item) but as an imperative rather than a condition, so the agent must infer the rule for when a live page fetch is preferable to a dataset lookup. Usage is implied by the field list but no explicit when-to-use or exclusions are given.

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