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

Annotations already declare readOnlyHint=true, openWorldHint=true, and destructiveHint=false, so safety is covered. The description adds genuine value beyond them by disclosing the billing model ($0.008 per page) and the returned fields (review text, recommendation status, author info), though it omits auth or rate-limit details.

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?

Three tight sentences, front-loaded with the core action and input source, then returns, then cost. Every sentence earns its place with no 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?

For a read-only fetch tool with no output schema, the description adequately covers the input provenance and returned content, and the pages parameter bounds are in the schema. Pagination/cost interplay could be slightly clearer, but nothing essential is missing.

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%, so the baseline is 3, and the description adds meaning by specifying that page_id is numeric and sourced from facebook_page_details. It does not describe the pages or get_sentiment semantics, but those are fully documented in 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?

States a specific verb and resource ('Get reviews of a Facebook page') and names the input source (numeric page ID from facebook_page_details), which clearly separates it from siblings like facebook_page_posts, facebook_page_photos, and place_reviews. An agent can identify this as the page-review endpoint without opening the 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 gives clear context by pointing out that the page_id comes from facebook_page_details, effectively routing the agent through the right prerequisite call. It lacks explicit when-not-to-use or named alternative tools, so it stops short of a 5.

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