update_workflow_instances_cancel

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It adds valuable context about the authentication requirement ('requires a registered application key'), which is crucial for usage. However, it doesn't describe what 'cancel' means operationally (e.g., whether it stops execution immediately, allows restart, affects related resources, or returns confirmation). The description doesn't contradict annotations since none exist.

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 extremely concise with just two sentences that each earn their place. The first sentence states the core purpose, and the second provides critical authentication information. There's zero waste or redundancy, and it's front-loaded with the main action.

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 tool has no parameters (schema coverage 100%) and no output schema, the description covers the basic purpose and authentication requirement adequately. However, as a mutation tool with no annotations, it should ideally describe behavioral aspects like what 'cancel' entails, whether it's reversible, or what confirmation is returned. The authentication note is helpful but doesn't fully compensate for the lack of behavioral context.

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 input schema has 0 parameters with 100% coverage, so there are no parameters to document. The description appropriately doesn't discuss parameters, which is correct for a tool with no inputs. It focuses on the action and authentication requirement instead.

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 the tool's purpose with a specific verb ('Cancels') and resource ('a specific execution of a given workflow'), making it immediately understandable. It distinguishes from siblings like 'update_workflow' or 'create_workflow_instances' by focusing on cancellation of executions rather than creation or modification.

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 provides no guidance on when to use this tool versus alternatives. It mentions an authentication requirement but doesn't specify prerequisites like having an existing workflow instance ID or differentiate from other cancellation tools like 'downtimes_cancel'. No explicit when/when-not or alternative usage is provided.

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