create_coupon

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

No annotations are provided, so the description carries the full burden. It mentions that the tool creates a coupon but lacks critical behavioral details: it doesn't specify required permissions, rate limits, whether the operation is idempotent, what happens on failure, or the expected output format. The description only covers basic parameter usage without broader context.

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 highly concise and well-structured: a clear purpose statement followed by two focused sentences explaining key parameter usage. Every sentence adds value without redundancy, and the information is front-loaded for quick understanding.

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?

Given the complexity (a write operation with 5 parameters), no annotations, and an output schema (which reduces the need to describe return values), the description is moderately complete. It covers the core action and some parameter logic but lacks behavioral context (e.g., permissions, side effects) and full parameter documentation, making it adequate but with clear gaps.

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 0%, so the description must compensate. It explains the semantics of 'is_percentage' and 'currency' parameters, clarifying their roles in percentage vs. fixed discounts. However, it doesn't cover 'name', 'discount_value', or 'is_active', leaving three of five parameters undocumented. This partial coverage meets the baseline for low schema coverage.

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's purpose: 'Create a new discount coupon on Stream.' It specifies the verb ('Create') and resource ('discount coupon'), making the action unambiguous. However, it doesn't explicitly differentiate from sibling tools like 'deactivate_coupon' or 'get_coupon' beyond the 'create' action.

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 provides no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites (e.g., authentication needs), compare it to sibling tools like 'list_coupons' or 'deactivate_coupon', or specify scenarios where coupon creation is appropriate versus other operations.

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