update_event

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

With no annotations, the description carries the burden and covers partial update semantics, return value ('updated event as a dict'), and error behavior ('ValueError: If event not found'). It omits permission/reversibility details, but the core behavior is transparent.

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 one-sentence summary is front-loaded, followed by clean Args/Returns/Raises sections. Every part adds value and the formatting makes it easy for an agent to scan.

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?

The description, combined with the output schema, gives enough to call the tool correctly: required UID, updatable fields, return shape, and error condition. Minor gaps remain around whether null clears a field and the calendar_name default, which are not explained.

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%, but the Args section documents all seven parameters, adding useful semantics such as ISO 8601 format for start/end and the provider-prefix requirement for calendar_name. Some entries are terse ('New title', 'New description') and null/default behavior is not explained.

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 a specific verb and resource: 'Update an existing calendar event by UID.' This clearly distinguishes update_event from sibling list/get/create/delete tools and from update_calendar_metadata.

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 clarifies this is for an existing calendar event and describes partial-update behavior ('Only provided fields are changed'). It does not explicitly list when-not-to-use or alternative tools, but the context is clear enough.

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