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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is covered. The description adds useful behavioral context by naming the returned fields (discounts, codes, availability, redeemed count, expiry) and the underlying GET endpoints, though it does not discuss pagination behavior.

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 tight sentences, front-loaded with the core list operation and scope distinction. The return fields and endpoint paths are packed efficiently with no redundant or filler text.

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 read-only list tool with a fully documented schema and safety annotations, the description covers the essential gaps: scope selection, returned fields, and endpoints. No output schema exists, but the description sufficiently explains what the caller will see.

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 all five parameters are already well documented. The description reinforces the form_id distinction but adds no syntax, format, or edge-case meaning beyond what the schema already provides.

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 states a specific verb and resource ('List GivingFuel coupons') and immediately distinguishes the two scopes: account-wide coupons versus coupons for a single form when form_id is supplied. This clearly separates it from sibling tools like get_coupon and create_coupon without needing to inspect the schema.

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?

It explains the key selection context: omit form_id for global coupons or provide it to scope results to one form. However, it does not explicitly name alternatives such as get_coupon for retrieving a single coupon, nor does it state when not to use this list operation.

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