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

Annotations already establish destructive=true, idempotent=true, readOnly=false, so the safety profile is covered. The description adds genuinely new behavioral context: out-of-scope batches are rejected before mutation, history is retained, and 'cancellation requested is not proof every target stopped' — an important asynchronous/partial-completion caveat an agent would not otherwise know.

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?

Three sentences, no filler, action front-loaded in sentence one with the caveats following. Each sentence carries distinct information (action, validation constraint, durability/partial-completion note). Slightly dense but appropriately sized.

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 destructive mutation tool with no output schema, the description covers the key operational concerns: scope validation, history retention, idempotent retry (via operationKey in schema), and the caveat that cancellation is not confirmed stoppage. The remaining gap is the thin parameter documentation, but the overall operational picture is reasonably complete.

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 only 25% — operationKey is documented with retry semantics, but batchId, projectId, and environmentId carry no descriptions. The description partially compensates by implying the scope relationship ('explicit project/environment', 'batch outside the selected scope'), but it does not explain the roles of the three undocumented identifiers, leaving a real gap.

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 specific verb ('cancel') and resource ('batch'), and refines it into two distinct actions: canceling unclaimed work and requesting cancellation of active customer-owned runners. It scopes to the explicit project/environment, which lets an agent distinguish this batch-cancel tool from siblings like firedrill_create_batch or firedrill_batch, though it does not name an alternative tool.

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?

It conveys a usage constraint ('a batch outside the selected scope is rejected before mutation'), which implies the caller must supply a batch within the target scope. However, it never states when to use this versus other lifecycle tools, nor any prerequisites or authorization expectations. Usage is implied rather than explicitly guided.

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