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

With no annotations, the description carries the full burden and does a solid job: it discloses the 2-credit cost, that empty results and failures are never charged, and the cache semantics (free 24h hit, default always fresh). These are meaningful behavioral details beyond the basic 'list' action, though it does not cover rate limits or detailed return structure.

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?

The description is short and front-loaded with the core purpose, but it redundantly states '2 credits. Costs 2 credits.' and largely repeats the schema's cache explanation. The redundancy makes it less crisp than it could be.

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?

Together with the fully described schema, the description is nearly complete: it covers the purpose, output fields, cost, cache behavior, and failure charging. The main gap is lack of sibling routing context, which is already accounted for in usage_guidelines; nothing needed for a correct call 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%, with detailed descriptions for url, cache, and limit, so the baseline applies. The description only restates cache behavior and credit cost already present in the schema, adding no new parameter-level meaning.

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 opens with a specific verb and resource — 'List a Facebook Page's events' — and adds the distinguishing output fields (local startDate, timezone, venue). This makes it clearly distinguishable from siblings like facebook_event_search (general event search) and facebook_event_details (details of a single event).

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 description implies a use case (listing events for a specific Facebook page) but provides no explicit when-to-use guidance or named alternatives. It does not tell the agent to prefer this tool over facebook_event_search or facebook_event_details, nor does it state any exclusions.

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