Cancel a scheduled postcard

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

Adds state requirement (before send_date, not production-locked) beyond annotations. Annotations include destructiveHint: true, idempotentHint: true. No contradiction.

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?

Two sentences, front-loaded with main action. 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?

Given one parameter, no output schema, and annotations providing some context, the description is complete by explaining the action, condition, and limitation.

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?

Only one parameter (id) fully described in schema (pattern and description). Description does not add additional meaning beyond schema, so baseline 3 applies.

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 (cancel), resource (postcard), and key condition (before send_date, not production-locked). It distinguishes from sibling tools like lob_postcards_create, get, list, preview.

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 clear context: cancel only before send_date and while cancellable. Excludes production-locked pieces. Does not explicitly name alternatives but context of siblings implies this is the only cancel tool for postcards.

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