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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description adds useful context: the owner-scope of the store, that no purchases occur in chat, that payment goes to the business's Stripe account, and that coupons on a membership only discount the first payment. Missing only return-volume/pagination behavior, which is minor for a read.

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 core action is buried behind a multi-clause preamble about store ownership, chat purchases, and Stripe payout that is tangential to listing coupons. The routing and field enumeration sentences earn their place, but the opening sentences are heavier than needed.

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 no output schema, the description compensates by listing returned fields and stating that an empty list means no coupons — giving the agent enough to interpret results. Slightly more on ordering or result size would complete it.

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?

One optional parameter (workspaceId) with 100% schema description coverage, so the schema already explains the default scoping. The description adds nothing about workspaceId, 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?

States a specific verb and resource: 'List the store's discount codes', and enumerates the returned fields (id, code, discount, uses, maxUses, expiresAt, active, product scope). It is clearly distinguishable from create_coupon and set_coupon_active which are both named.

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?

Explicitly routes to the alternatives: create_coupon for creation and set_coupon_active with an id for toggling. It also frames the operation as store-administration scoped. No explicit 'do not use when' exclusion, but the sibling routing is concrete.

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