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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered, but the description adds nothing beyond them - no indication of what fields 'details' includes, whether the id is a page slug or numeric id, or any auth/rate-limit behavior.

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?

Extremely short and front-loaded, but it is under-specified rather than efficient - a three-word fragment cannot earn much credit for structure when it omits the only useful detail.

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, return values need not be explained, but for a lookup tool the description should still clarify what a 'page detail' covers and how the id is sourced. Given the total absence of that context, the definition is thin.

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% with a single 'id' parameter labeled 'Resource identifier.', so the schema carries the burden; per the calibration baseline this yields a 3. The description adds no extra meaning about the expected id format (slug vs. numeric).

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 the resource (a Facebook page) and that it returns 'details', which is enough to infer a single-page lookup by id. But it is a bare noun phrase with no verb and no differentiation from the many sibling page/item tools such as datasets_facebook_pages_item or facebook_marketplace_search.

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?

There is no when-to-use guidance, no prerequisites, and no mention of alternatives. An agent must infer from the name alone that this is the single-item fetch rather than a search.

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