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

Annotations already cover safety (readOnly, idempotent, non-destructive, closed-world), so the description only needs to add context. "The first one free" does add useful commercial context (subsequent responses appear to be paid), but the description never says what the tool actually produces or whether it depends on an external merchant account.

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?

Three short sentences, no filler, and the audience/condition (merchant with an open chargeback) is front-loaded. Slightly informal tone ("the first one free") trades some precision for compactness, but nothing is wasted.

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?

With two optional parameters, no output schema, and full annotation coverage, the remaining gap is the return behavior: an agent cannot tell whether it gets prose guidance, a generated draft, or a redirect. For a guidance-style tool that ambiguity matters, and the description does not resolve it.

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% and both parameters are documented with examples (13.1, Visa 10.4) and network enum values. The description only echoes optionality with "if you know it," adding no syntax or format detail beyond the schema, 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?

"Explains how to get a custom response" gives a rough sense of the resource (dispute-response guidance), but the phrasing is vague — it is unclear whether the tool returns explanatory text, a generated response draft, or a link. Siblings like get_pricing and lookup_reason_code are not referenced, so the boundary between this tool and reason-code lookup is left implicit.

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?

"For a merchant with a chargeback open now" is a usable precondition, and "Pass the reason code if you know it" signals the optional path. However, no alternative is named and there is no guidance on when to use lookup_reason_code first to obtain the code this tool accepts.

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