Facebook Page insights

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

Annotations already declare read-only, idempotent, non-destructive, open-world. The description adds two genuinely behavioral facts not in the annotations: the 90-day maximum window per request and that page_media_view replaces the deprecated impressions metric. It does not cover pagination or return shape, but the annotation coverage lowers the bar.

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?

A single dense sentence with the resource stated first and the 90-day cap last. The mid-sentence parenthetical about the deprecated impressions metric slightly interrupts the metric list, but no sentence is wasted.

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?

For a 5-parameter, no-required-parameter, read-only insight tool with full schema descriptions and strong annotations, the description covers scope, allowed window, and the key metric deprecation. It omits only return-granularity details, which is acceptable given there is no output schema.

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%, so the baseline is 3, but the description adds real semantic value the schema lacks: it clarifies that page_media_view is the non-deprecated replacement for impressions, which helps an agent pick the correct enum value. Other parameters (page_id, client_id, dates) are left entirely to the schema.

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?

Names a specific verb+resource: Facebook Page insights, per day and in total, and enumerates the metric families (media views, post engagements, follows/unfollows, total actions). It is clearly the page-level insights tool, distinguishable from meta_insights and meta_ig_insights by resource, though it never names those siblings explicitly.

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?

The 90-day-per-request constraint states a usage boundary, but there is no explicit when-to-use/when-not guidance relative to the many sibling insight tools (meta_insights, meta_ig_insights, openai_ads_insights). Usage is only implied by the resource name.

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