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

Annotations already declare readOnlyHint=true, openWorldHint=true, destructiveHint=false, so the safety profile is covered. The description adds genuinely new context the annotations cannot express: a per-request price of $0.008, and the fact that the response carries downstream identifiers other tools depend on. It omits error behavior for invalid or missing pages.

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?

Two sentences, zero filler. The core action and returned fields are front-loaded, and the billing note is placed last where it does not obstruct the primary 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, and the description compensates well by enumerating the returned fields and the cross-tool identifiers. Pricing is disclosed. What remains missing is failure behavior (invalid URL, page not found, rate limiting), a minor gap for a single-parameter read 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?

One parameter at 100% schema coverage, so the schema already documents the url argument and gives an example. The description adds no syntax, format, or validation detail beyond the schema, which is the expected baseline when structured data does the work.

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?

Specific verb+resource ('Get a Facebook page by URL') plus an explicit enumeration of what is returned (name, page_id, follower/like counts, categories, contact info, rating, verification status). This clearly separates it from search_facebook_pages and the sibling facebook_page_posts/photos/reels tools.

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?

No explicit when-to-use vs search_facebook_pages, and no prerequisite that a page URL must already be known. The description does imply usage by noting the returned delegate_page_id and reels_page_id are required by facebook_page_videos and facebook_page_reels, which is a useful chaining signal but not full guidance.

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