update_event

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

With no annotations, the description carries the behavioral disclosure burden. It discloses that only provided fields are modified and others remain unchanged, which is important partial-update behavior. It also states the return format (JSON string), adding transparency beyond the opaque schema.

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 opening paragraph is concise and front-loaded, but the Args block largely duplicates the input schema's parameter descriptions, adding redundancy. The Returns line is useful but the overall structure could be tighter.

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?

Given the output schema exists and parameters are fully described in the schema, the description adequately covers the patch-style update behavior and return type. It does not explain error cases or authorization, but those are not essential for a simple update tool with a rich schema.

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 the baseline is 3. The description repeats parameter names and adds minimal new meaning beyond the schema, mostly reinforcing the partial-update semantics.

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 clearly states 'Update an existing calendar event' with a specific verb and resource. It distinguishes itself from siblings like create_event, delete_event, and duplicate_event.

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?

Provides clear context that this tool modifies existing events and explicitly instructs to only provide fields to change, implying partial updates. It does not explicitly mention when not to use it or name alternatives, but the existing-event emphasis differentiates it from create/delete tools.

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