cycles_create_event

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

With no annotations, the description must provide behavioral insights. It mentions 'applied atomically to all derived scopes' and 'directly without reserve/commit lifecycle,' giving useful context. However, it omits details on idempotency, error handling, or duplicate management, which are relevant given the idempotencyKey parameter.

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, efficiently stating purpose and usage context without redundancy. It is front-loaded with the core action ('Record a usage event directly'), making it easy to parse.

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 complexity (8 parameters, nested objects, no output schema), the description fails to provide sufficient context. It does not explain the meaning of required parameters like idempotencyKey or actual, nor the role of optional fields like overagePolicy or metrics. The agent would be left guessing how to structure the request.

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%, so the description must compensate for understanding parameters. It provides no information about the eight parameters, including required ones like idempotencyKey, subject, action, and actual. The nested structures and enums are entirely unaddressed, leaving the agent without guidance on how to populate these fields.

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 records a usage event directly without the reserve/commit lifecycle, for fire-and-forget metering of completed operations. It distinguishes this tool from siblings like cycles_reserve and cycles_commit by specifying it's for use when pre-estimation is not available.

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 explicitly says when to use the tool: 'for fire-and-forget metering of completed operations where pre-estimation is not available.' This implies the alternative is using the reserve/commit lifecycle when pre-estimation is available. While not naming sibling tools explicitly, the context is sufficient.

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