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

readOnlyHint already signals safety, and the description adds that the tool returns a paged collection and maps to Ecwid's GET /discount_coupons endpoint. This gives the agent useful behavioral context beyond the annotation without contradicting it.

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 concise sentences cover the action, resource, optional filters, pagination, and REST endpoint. There is no filler, and the core purpose is front-loaded.

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 list operation with zero required parameters, full schema documentation, and a read-only annotation, the description is nearly complete. It covers purpose, filters, pagination, and endpoint; only a more explicit note about default pagination or response shape would push it higher.

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%, so every parameter is already documented with its own description. The tool description names three filters at a high level but adds no extra meaning over the schema, matching the baseline for full 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 states a specific verb ('list') and resource ('the store's discount coupons'), and names the optional filters and paged behavior. This clearly separates it from the sibling get/search/update tools, even without naming an alternative.

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 context is clear: use this tool to list discount coupons, optionally filtered by code, type, or availability. There are no explicit when-not-to-use instructions or named alternatives, but none of the siblings covers discount coupons, so the usage context is sufficient.

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