Extend Reservation TTL

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

The description adds context beyond annotations by stating that the reserved amount is unchanged and that it acts as a heartbeat, which aligns with the idempotent and non-destructive hints. It does not contradict 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 concise, with two sentences that front-load the core action and then provide additional context. No unnecessary words.

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?

The description provides the essential purpose and a key usage scenario, but lacks details on parameter semantics (e.g., extendByMs limits, idempotencyKey purpose) and does not mention whether the operation can fail or any side effects. The presence of an output schema partially mitigates return value documentation, but parameter documentation is entirely absent.

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?

With 0% schema description coverage, the description does not explain individual parameters (e.g., what extendByMs represents, what idempotencyKey is for) beyond the implied context from the main description. The agent must infer parameter meanings from the tool title and description.

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 action ('Extend the TTL') and the resource ('active reservation'), and explicitly notes what it does not change, distinguishing 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 a specific use case ('heartbeat for long-running operations') and a clear behavior note ('does not change the reserved amount'), but does not explicitly contrast with alternatives like cycles_reserve or cycles_commit.

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