Get an event

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

Annotations already declare readOnly, idempotent, openWorld, and non-destructive behavior, so the bar is lowered. The description adds valuable behavioral context by listing the response contents, covering recurrence-related behavior, and noting that instance ids are accepted. No contradictions with 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?

The description is a single well-structured sentence that front-loads the core action and then lists relevant response fields. It is somewhat long, but the field enumeration is justified because there is no output schema to carry that information.

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 no output schema, the description compensates by detailing the return fields and addressing series/instance behavior. It does not mention not-found or error behavior, but for a simple read operation covered by strong annotations and complete parameter schemas, this is reasonably complete.

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. The description does not explain the parameters beyond what the schema already covers, but it does add context about instance id handling that aligns with the schema's event_id documentation. No significant additional semantic value beyond structured fields.

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 a specific verb ('Fetches'), a specific resource ('one event by id'), and enumerates the exact fields returned. This clearly distinguishes it from list_events and list_event_instances, and the additional note about series masters vs instances removes ambiguity.

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 clear this is for fetching a single event by id and explicitly says it works for both series masters and individual instance ids. It does not name sibling alternatives or give exclusion criteria, but the single-event-by-id framing gives strong contextual guidance.

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