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

Annotations only declare readOnlyHint=true, so the description usefully adds that results are cached by Breeze and may lag up to 15 minutes, plus that enabling schedule changes the response to an array of {id, start} only. It does not cover auth/permission needs or pagination, but the staleness and response-shape disclosures are real added value.

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 with the core action front-loaded and no filler. The trailing 'Breeze: GET /api/events/list_event' is endpoint trivia of marginal use to an agent but costs little.

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?

There is no output schema, so the description carries the return-value burden and does describe both response shapes; combined with annotations covering the read-only profile, an agent has enough to call it correctly. Permission requirements and pagination for large series remain unstated.

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 goes beyond the schema's terse 'Also return other instances in the same series' by explaining the consequence of the schedule flag: the response degrades to an array of {id, start} only. It adds no detail for details, eligible, schedule_limit, or schedule_direction, so it is not a full 5.

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 ('Fetch one event instance') and immediately qualifies scope with the optional series expansion, which distinguishes it from the sibling breeze_list_events. An agent can tell what it returns 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?

The description makes the schedule flag's purpose explicit ('optionally with the other instances in its series'), which implies when to set it, but it never names an alternative tool (e.g. breeze_list_events) or states when not to use this one. Clear context, no explicit routing.

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