Update calendar event

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

With no annotations provided, the description carries full burden for behavioral disclosure. It only states 'partial update' which hints that unspecified fields remain unchanged, but it does not disclose that this is a destructive/irreversible write, mention permissions, or explain error behavior. For a mutation tool, this is a significant gap.

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, front-loaded sentence with no redundant information. Every word contributes to understanding the tool's purpose and behavior, making it very concise and well-structured.

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 9 parameters and no output schema, the description is too minimal. It does not explain the return value, the default for calendarId, how account affects behavior, or how fields interact (e.g., start/end validation). The one-liner is insufficient for a tool of this complexity.

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 67%, leaving summary, location, and description undocumented. The description adds the important semantic that the update is partial, meaning only provided fields are modified. However, it does not compensate for the three parameters with missing schema descriptions, so the 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 'Update fields of an existing event (partial update)' uses a specific verb and resource, clearly indicating it modifies an already-created event. It also distinguishes itself from sibling tools like create_event, get_event, and delete_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?

The phrase 'existing event' and 'partial update' provides clear context that this tool is for modifying, not creating or deleting. It implies the when-to-use case, though it does not explicitly name alternatives or list exclusions. This absence of explicit exclusions keeps it at a 4 rather than a 5.

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