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

readOnlyHint=true already declares the safety profile, so the description's main extra is the REST endpoint mapping, which is modestly useful. It says nothing about pagination or result ordering behavior, which is a common concern for list endpoints.

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 short sentences, zero waste, with the core purpose front-loaded and the endpoint detail trailing as secondary reference.

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 single-parameter read-only list tool with full schema coverage and annotations declaring readOnly, the description is sufficient to call it correctly. Only the absence of pagination/return-shape hints keeps it from a 5.

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% with a single product_id parameter documented in the schema, so the baseline of 3 applies. The description restates the product-scoped nature but adds no format, type, or grouping detail beyond the schema.

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 (List) and resource (offer codes / discount codes) scoped to a product, and names the REST endpoint. An agent can distinguish it from gumroad_get_offer_code (single) and gumroad_create_offer_code without opening any 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?

Use is implied by the resource scope — list the codes attached to a given product — but there is no explicit when-to-use vs. gumroad_get_offer_code or gumroad_list_products, nor any exclusion or prerequisite guidance.

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