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

Annotations already declare readOnly and openWorld; the description adds meaningful context beyond them: 'public' events only and an explicit '1 credit' cost, plus the breadth of returned data. It omits error behavior and the cache_max_age effect.

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, front-loaded field enumeration, and trailing cost note — no wasted text. Efficient and easy to parse.

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?

No output schema exists, but the description enumerates the returned fields, states the credit cost, and notes public-only scope. It leaves the cache_max_age behavior unexplained but is otherwise adequate for a simple 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?

With only 50% schema coverage, the description should compensate but adds no meaning for url or cache_max_age. It only says the resource is a 'public Facebook event'; cache_max_age is undocumented in both schema and description.

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 clearly states it returns full details for a single public Facebook event and enumerates the returned fields (description, times, venue, host, ticket price). However, it never names the sibling distinction from facebook_eventsSearch or facebook_cityEvents, which an agent must infer.

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?

'Full details for one public Facebook event' implies retrieval-by-identifier usage after discovery, but there is no explicit when-to-use vs. search/cityEvents guidance and no exclusions. The agent must infer the workflow.

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