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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the destructive nature is structured. The description adds valuable behavioral context beyond annotations: it notifies attendeescias a side effect, only applies to events organized by the connected account, and warns to confirm before acting. This enriches the safety profile without contradicting 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 two sentences with no filler. The primary action and scope come first, followed by a concise differentiator and a practical caution. Every sentence earns its place.

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 destructive, non-idempotent operation, the description covers the key context: what it cancels, its side effect, how it differs from the delete sibling, and a confirmation warning. With no output schema, it doesn't need to explain returns. The main small gap is that it doesn't mention parameter prerequisites, but those are thoroughly handled in the schema, so overall it is nearly 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?

The tool description itself does not add parameter semantics, but the input schema covers 100% of the parameters with detailed descriptions (e.g., event_id says how to obtain it and never pass a title/date; calendar_id warns against names). Since the schema already documents param meaning, a baseline of 3 is appropriate—no extra value is needed or provided.

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 ('Cancel') with a clear resource ('an event organized by the connected account') and a distinct side effect ('notify attendees'). It also explicitly differentiates from the alternative 'deleting an event only from the user's calendar', which aligns with the sibling calendar_delete_event. This leaves no ambiguity about the tool's function.

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 gives an explicit when-to-use: cancel events organized by the connected account when attendees should be notified. It also names the alternative scenario ('deleting an event only from the user's calendar') and adds a caution to 'confirm the exact event before cancellation', which guides safe usage.

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