Preflight Budget Check

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

The description transparently states it does not create a reservation, aligning with annotations (destructiveHint=false, idempotentHint=true). It clarifies the read behavior beyond the annotations, ensuring the agent understands it is a non-destructive check.

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 very concise with two short sentences, front-loading the core purpose and usage guidelines. Every sentence adds value without redundancy.

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?

Despite having a clear purpose, the description completely omits parameter semantics for a tool with 5 parameters (3 required) and nested objects. The agent lacks crucial information to correctly construct inputs.

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 JSON schema has no parameter descriptions. The description provides no explanation of any parameters (action, subject, estimate, metadata, idempotencyKey), leaving the agent to infer from schema alone.

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 it is a 'preflight check' to ask if an action is allowed without reserving budget, and explicitly says it does not create a reservation. This distinguishes it from sibling tools like cycles_reserve.

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?

Provides explicit guidance: 'Use at workflow start to decide strategy' and directs to cycles_reserve for concurrency-safe budget locking, giving a clear when-to-use and when-not-to-use with an alternative.

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