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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the description's main added value is the pricing disclosure "15 points per returned record" — a genuinely useful behavioral constraint absent from structured fields. It also implies a per-record billing model, which tells the agent to avoid broad/duplicate calls. It stops short of describing lookup failure behavior or whether name matching is fuzzy.

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?

One compact sentence front-loads the resource and input modes, followed by a short cost statement — nothing is wasted. The field enumeration is long but each item is informative rather than filler.

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 no output schema, the description must convey return content, and it does so by listing the field categories retrieved; it also discloses cost. What is missing is failure/empty-result behavior and a note on how name vs ID lookups differ, for an open-world scraper 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?

Schema coverage is 100% and the schema already documents the single url parameter with an example, so the description's restatement ("by URL, name or ID") adds little beyond confirming the accepted input forms. Baseline 3 is appropriate; no additional syntax, casing or lookup-precedence rules are given.

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 states a specific verb+resource ("Facebook page details") and enumerates exactly what is returned: categories, intro, likes, followers, rating, contact fields and latest posts. It is clear what the tool fetches, though it does not explicitly distinguish itself from nearby siblings like run_facebook_page_contacts or run_facebook_posts.

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 explicit when-to-use guidance and no mention of alternatives, despite the sibling list containing run_facebook_page_contacts, run_facebook_posts, run_facebook_reviews and run_facebook_search, all of which overlap with the fields listed here. An agent must infer from field overlap which tool to pick.

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