query-my-coupons

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

Annotations already declare readOnlyHint=true, and the description reinforces it while adding context the annotation cannot: it will not mutate state by claiming new coupons, takes no parameters, and operates on fictional demo data not connected to official McDonald's services. The demo-data caveat is genuinely useful behavioral disclosure; only the return format is left unstated.

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?

Three short sentences, each earning its place: purpose, read-only/alternative routing, and the data caveat. The core purpose is front-loaded before the qualifications.

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?

For a parameterless read tool with no output schema, it covers everything an agent needs: what it returns (coupon names), the safety profile, the no-parameter fact, and the demo-data limitation. Nothing material is missing.

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?

Zero parameters, so the baseline is 4. The description explicitly confirms 'no parameters', which is consistent with the empty schema and leaves no ambiguity.

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 and resource: listing the names of coupons already claimed and usable by the current account. The scope (already-claimed, usable) is precise enough to distinguish it from other coupon operations, and it names the sibling-like alternative auto-bind-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?

Gives explicit when-not guidance ('won't claim new coupons') and routes the agent to the correct alternative ('to claim coupons use auto-bind-coupons'). Nothing is left to inference about which tool handles which intent.

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