Update AddEvent Event

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

Annotations already indicate non-read-only, idempotent, non-destructive behavior. The description adds valuable context beyond that: partial-update semantics, 404/400 error handling, and the note that validation failures return an error. It does not contradict the 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 well-structured with clear sections (Args, Returns, Examples, Error Handling, Don't use when). It front-loads the core purpose and each sentence earns its place, providing useful examples and error details without redundancy.

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?

For a tool with 21 parameters, the description covers the essential context: partial updates, error handling, return type (updated event object as JSON), and usage examples. It could have elaborated on edge cases (e.g., mutually exclusive fields), but the schema handles those details, and no output schema exists, so the return-type statement is sufficient.

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 100%, so every parameter already has detailed meaning. The description adds a few example parameter uses (datetime_start, location) and clarifies that event_id is required while all others are optional, but it largely relies on the schema. Baseline 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 opens with 'Updates an existing event'—a specific verb + resource. It also clarifies partial-update semantics ('Only the fields you provide are changed; everything else is left as-is'), which distinguishes it from a full replace or create, and explicitly contrasts with addevent_create_event in the 'Don't use when' note.

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?

It explicitly states when to use the tool ('Only the fields you provide are changed... include only what's changing') and when not to ('Don't use when: the event doesn't exist yet'), naming the alternative (addevent_create_event). The examples (moving a meeting, changing location) further clarify common usage scenarios.

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