Delivery: cancel parcel [sandbox]

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

Annotations already indicate destructiveHint=true and readOnlyHint=false. The description adds context that the operation is a cancellation on behalf of the receiver and returns a success status, but does not discuss side effects or reversibility. It is consistent with 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 (4 sentences), front-loads the core purpose, and efficiently provides constraints and differentiation without extraneous 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?

Given no output schema, the description mentions 'returns a success status,' which is adequate. It provides essential context about sandbox, partner-only, and relationship with sibling. The tool has 4 parameters fully described in schema, so the description completes the picture.

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 100%, so the description does not need to add much. It reiterates the actor=receiver constraint but does not elaborate on dryRun or idempotencyKey beyond the schema. The description adds marginal value over the schema.

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 verb (cancels), resource (test parcel), scope (sandbox), and actor (receiver). It also distinguishes from the sibling delivery_v1_cancel_parcel by noting the base contract with an actor field.

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 specifies that only parcels created via delivery_create_sandbox_parcel_v2 can be cancelled, and that it is for delivery-service PARTNERS only. It contrasts with delivery_v1_cancel_parcel, providing clear guidance on when to use this tool vs the alternative.

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