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

Discloses key behaviors: patch operation, clearing caps via boolean flags, renaming is allowed and preserves patron redemption data, and access restriction requires proof. With no annotations, this is thorough, though it could mention idempotency or behavior for sending unchanged fields.

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 four sentences, each adding distinct value: purpose, usage pattern, special behavior, and access restriction. It is well-structured and front-loaded with the core action.

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 the 10-parameter schema with 0% description coverage and the presence of an output schema, the description covers main editing behavior, special clearing, renaming effects, and access. Missing a description of dpop_token and the specific editable fields reduces completeness slightly.

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%, so the description must compensate. It explains the clear_uses_per_patron and clear_total_uses flags and mentions renaming the 'name' field, but does not describe other parameters like total_uses, discount_percent, or dpop_token. This partial coverage places it at a 3.

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 'Patch a coupon's editable fields,' providing a specific verb and resource. It distinguishes from sibling tools like mint_coupon and delete_coupon by focusing on updating existing coupons.

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 advises to pass only changed fields and explains special clear flags, plus notes the access restriction to operators. It implies when to use this tool (for modifying a coupon) and when not (e.g., for creating or deleting), but doesn't explicitly name alternatives.

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