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

readOnlyHint=true already covers the safety profile, and the description adds the actual returned fields (token, Stripe id, leads, conversions, archived), which is valuable because no output schema exists. It still says nothing about pagination behavior or result ordering, leaving a small gap.

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?

A single dense sentence is front-loaded with the core action and includes the source endpoint and field list efficiently. The parenthetical field enumeration is slightly listy but earns its place given the absent output schema.

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 simple read-only list tool with fully documented params, the description covers purpose, filtering, and return fields. Pagination is handled by the schema, and no output schema means only ordering/pagination semantics are left implicit.

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?

With 100% schema description coverage, the schema already documents page, limit, and affiliate_id semantics. The description's 'optionally for one affiliate' merely mirrors affiliate_id without adding syntax or format detail, so the baseline 3 applies.

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 gives a clear verb+resource ('List affiliate coupon / promotion codes') and enumerates the returned fields, so an agent knows exactly what it retrieves. It does not explicitly name the sibling 'get_affiliate_coupon' as the singular alternative, but the list-vs-get distinction is inferable from the name.

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?

It notes that results are 'optionally for one affiliate,' which implies when the affiliate_id filter applies, but there is no explicit when-to-use/when-not guidance or named alternatives among the many sibling tools. Usage is only implied.

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