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

Annotations already declare readOnly, openWorld, idempotent, and non-destructive behavior. The description adds valuable behavioral context beyond that: it raises a not-found error for invalid event_id and clarifies the credit behavior for inline data. This helps an agent predict runtime outcomes.

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 front-loaded, with the core purpose in the first sentence, usage guidance in the second, and error/cost behavior in the third. Every sentence earns its place and there is 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?

With an output schema present, the description covers the return contents, the not-found behavior, the credit profile, and the discovery/batch routes. The combination of annotations, schema, and description gives an agent everything needed to correctly select and invoke this 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%, with each parameter already meaningfully documented including defaults, valid values, and credit impact. The description only repeats the credit information and does not add substantially new parameter meaning, so a baseline score of 3 is appropriate.

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 'Get a single event with participants and venue', which names the exact resource, scope, and expected return content. It explicitly distinguishes itself from discovery and batch siblings by referencing list_events/query_events and batch_get_events.

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 explicitly says to 'Use list_events / query_events to discover ids first, or batch_get_events to fetch several ids in one call', which tells the agent when to use this tool versus alternatives. It also clarifies that odds and intelligence can be inlined with no additional credit, so cost-aware selection is possible.

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