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

Beyond the annotations (which already cover read-only and open-world access), the description discloses retrieval method (residential proxy), the logged-out visibility constraint, and the payment model, including that failed calls are not charged. That is exactly the kind of operational context an agent needs before calling a metered endpoint.

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: the first front-loads the resource and its returned fields; the second adds cost and payment mechanics. The field enumeration is long but informative, and there is no filler. Slight density in the comma list keeps it from being a 5.

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?

An output schema exists, so the field list slightly duplicates structured data, but the description still contributes the critical constraint (public/logged-out events only) and cost behavior. Nothing an agent needs to call the tool correctly appears to be 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% and the single 'page' parameter is documented with examples of accepted formats (username, numeric id, URL). The description adds no further parameter detail, so it sits at the baseline where the schema 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?

It names a specific resource and scope ('Events listed on a Facebook Page's Events tab') and enumerates exactly what is returned (event id, name, date text, place, city, cancelled flag, organiser, link, Page name). This makes it clearly distinguishable from sibling tools like social_facebook_posts, social_facebook_photos or social_facebook_pages, which cover different Page surfaces.

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?

Usage is only implied: 'logged-out view' signals that only publicly visible events are returned, which hints at when the tool is and isn't suitable. However, there is no explicit guidance on when to choose this over siblings such as social_facebook_posts, nor any stated exclusions or prerequisites.

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