list_discounts

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

No annotations are provided, so the description must cover behavioral traits. It only mentions the API key requirement, but omits details about read-only nature, return format, pagination behavior, or error handling. The tool is likely read-only, but this is not explicitly stated, and there is no disclosure of side effects or limitations.

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, consisting of two sentences: one for purpose and one for the prerequisite. Every sentence is necessary and directly useful, with no redundant or extraneous information.

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 listing tool with 2 parameters and no output schema, the description covers the basic purpose and a key prerequisite. However, it lacks context on return structure (e.g., array of discount objects), pagination behavior, and error conditions. Given the absence of annotations and output schema, additional completeness would be beneficial.

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 fully describes both parameters (limit, offset) with descriptions, achieving 100% schema coverage. The description adds no additional meaning beyond the schema, so the baseline score 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 clearly states the tool lists discount codes in the Karrito store. The verb 'list' and resource 'discount codes' are specific, and it distinguishes from mutation siblings like create_discount and delete_discount. However, it does not differentiate from other list tools such as list_my_products or list_categories, keeping the score from being a 5.

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 only usage guideline is the requirement of the KARRITO_API_KEY environment variable. There is no guidance on when to use this tool versus alternatives like search_catalogs or list_my_products, and no mention of when not to use it. The absence of contextual usage advice limits the score.

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