delete_activities_by_activity_id

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

Annotations already declare destructiveHint=true, idempotentHint=true, and readOnlyHint=false, covering safety and mutation semantics. The description adds slight context with 'Cancel a running activity', implying this affects an in-progress operation. However, it doesn't clarify whether the activity is actually deleted from history, whether it can be resumed, or what side effects cancellation might trigger (e.g., stopping a transcode or download). With annotations carrying the safety burden, a 3 is fair.

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 compact and efficient. The first line delivers the core semantic ('Cancel a running activity'), followed by the endpoint and a brief Args block. No wasted words. The Args section is somewhat redundant with the schema but acceptable given it re-uses the docstring convention. Slight deduction for redundancy of repeating the parameter in docstring format when schema exists.

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 single-parameter, destructive, idempotent operation with an output schema present, the description covers the essentials. An agent knows what to call, what parameter to supply, and what effect to expect. Gaps include: what happens if the activity is already finished or doesn't exist, and whether cancellation returns the activity state or an empty response. The output schema partially covers return values. This is adequate for the tool's low 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 0%, meaning the schema provides no description for activity_id beyond 'type: string' and 'title: Activity Id'. The description compensates by explaining exactly what the parameter is: 'The UUID of the activity to cancel.' This adds real semantic value beyond the bare schema. Given the low coverage, the description's parameter explanation is sufficient for an agent to populate it correctly.

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 clear verb and resource: 'Cancel a running activity.' This is specific and distinct from sibling tools. The description also includes the HTTP endpoint. However, the term 'cancel' differs from the tool name's 'delete' — the description clarifies that deleting an activity means canceling it, which adds value. It doesn't explicitly differentiate from list_activities or other activity-related siblings, but the purpose is clear.

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 implies usage: cancel an activity when it is running. It doesn't explicitly state when NOT to use it or name alternatives. There are no sibling tools with similar naming patterns for activities cancellation, so no explicit routing is needed. The openWorldHint annotation suggests the agent should explore, but the description is minimal on situational guidance. Adequate but minimal.

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