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

Annotations already provide readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is covered. The description adds meaningful behavioral details beyond annotations: empty list behavior when no discounted cards exist, error behavior for a nonexistent id, multiple-seller comparison purpose, and the requirement to always show the tracked url as a clickable link. These are precisely the non-obvious behaviors an agent needs to invoke and present results correctly.

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 front-loaded with the core result, then covers usage conditions, edge cases, and output presentation in a compact set of sentences. Every sentence carries distinct information: result type, comparison purpose, when to use, when not to use, empty/error behavior, and required presentational format. No filler or redundancy weakens it.

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?

The tool is simple with one parameter, strong annotations, and a rich output schema, so the description does not need to restate return types. It covers the selection condition, the alternative tool, edge-case behavior, and user-facing presentation requirements. This is fully sufficient for correct invocation and result handling.

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%, and the parameter description in the schema already explains that store_id is GotCashback's numeric id from an earlier result and directs name-only cases to the by-name tool. The tool description adds little parameter meaning beyond echoing 'numeric store_id' and the known-id condition, so baseline 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 clearly states the tool returns discounted gift cards for one store by numeric store_id and emphasizes comparison across multiple sellers. It distinguishes itself from the sibling get_gift_cards_by_store_name by explicitly naming the ID-based vs name-based route, so an agent can disambiguate without opening 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?

The description gives explicit when-to-use guidance: only when a store_id is already known from an earlier result. It also explicitly directs the agent to call get_gift_cards_by_store_name when only a store name is available and tells it not to look up the id first, which prevents a costly mistake. Additional presentation instructions add further practical guidance.

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