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

Annotations already declare readOnly, idempotent, and non-destructive behavior. The description adds valuable behavioral context beyond this: only public events are accessible, inactive/private events are unavailable, unknown timezones remain null, and the default date window is precisely defined. No contradiction exists between the description and annotations.

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 short sentences, front-loaded with the primary purpose, and every sentence contributes behavioral or usage value. There is no redundancy or 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, return value documentation is unnecessary. The description covers public-only access, date window defaults, timezone behavior, and availability constraints. It is slightly incomplete on exact date formats, but the schema and required event_id field fill most of the remaining gap.

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 description coverage is 0%, so the description must compensate. It does add meaning for date-related parameters by explaining the default window and user-local date expectation, but it does not describe event_id or language semantics. This is partial compensation rather than full parameter documentation.

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 names a specific verb ('Read'), a clear resource ('public event facts and dated occurrences'), and a window constraint. It does not explicitly distinguish itself from siblings like search_events, but the resource is specific enough that an agent can infer the difference between reading a single event's facts and searching for 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 provides clear context for when to use the tool by explaining the default UTC window and instructing the caller to pass user-local dates for today/tonight. It does not state exclusions or name alternatives, but the usage context is actionable and unambiguous.

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