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

Goes well beyond the annotations (destructiveHint/idempotentHint/openWorldHint): it discloses that a success releases the full fee hold, that cross-account store declines record store.declined with cancel_reason store_declined, and that post-pickup returns not_cancellable. This is rich mutation-outcome context, not repetition of structured data.

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?

Four tight sentences, front-loaded with the core action and window, then branching to the special store-decline case and the failure/retry behavior. No filler.

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?

No output schema, but the description covers return behavior ('not_cancellable') and retry safety ('Safe to retry') plus side effects, so an agent can call it correctly. The only meaningful gap is the undocumented robomart_version parameter.

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% and neither parameter (delivery_id, robomart_version) is mentioned in the description. The version enum in particular is left entirely unexplained, so the description fails to compensate for the absent schema documentation.

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?

States a specific verb+resource ('Cancel a delivery') and immediately scopes it ('before pickup'), which cleanly separates it from siblings like book_delivery and track_delivery. The added consequence of a successful cancellation makes the purpose unambiguous.

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?

Explicitly names the window ('before pickup'), an authorized actor case ('owner of an open store ... on another account's booking inside the decline window'), and the when-not condition ('After pickup the call returns not_cancellable'). An agent knows exactly when this applies and when it will fail.

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