payments_update_coupon

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

Annotations indicate readOnlyHint=false, openWorldHint=true, idempotentHint=true, and destructiveHint=false. The description does not add any behavioral context beyond the name, such as what gets mutated, authentication needs, or side effects. Given the annotations present, the description contributes minimal additional transparency.

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 extremely concise at two words, but it is under-specified rather than efficiently structured. It omits critical information that an agent would need, making the brevity a deficiency rather than a benefit.

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?

With 14 parameters, including nested objects and no output schema, the description is grossly incomplete. It provides no information about required fields, behavior, return values, or usage context, making it nearly useless for an agent attempting to call the tool correctly.

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?

The input schema has 100% description coverage for all 14 parameters, so the schema fully documents parameter meaning. The description itself provides no parameter information, which is acceptable since the schema carries the weight. Baseline of 3 is appropriate.

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 'Update Coupon' clearly identifies the verb (update) and resource (coupon), which distinguishes it from other tools like payments_create_coupon. However, it lacks any specifics about what can be updated or any additional context, so it is only minimally useful beyond the tool name itself.

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?

No guidance is provided on when to use this tool versus alternatives like payments_create_coupon or payments_delete_coupon. It does not state prerequisites, context, or when this update is appropriate, leaving the agent without direction.

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