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

Annotations only declare readOnlyHint=true; the description goes further by disclosing result ordering ('newest first'), the shape of returned values (amount in cents, currency, state with enumerated values) and the underlying GET /v1/commissions endpoint. It stops short of discussing pagination behavior or default result limits, which is the remaining 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?

Two dense sentences: the first leads with the core action and return shape, the second covers filtering and expansion. Every clause carries information and the endpoint is tucked at the end rather than 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?

With no output schema, the description carries the burden of describing returns and partially does so (amount, currency, state, ordering), plus filter and expand options. Pagination behavior and the unpaginated default are not addressed, which is a minor omission for a list tool.

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 coverage is 100%, so the baseline is 3, but the description adds meaning beyond the schema by enumerating the state values and clarifying what expand actually returns ('the sale (with referral, customer and affiliate) or campaign'). It does not mention page/limit, though those are self-describing in 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 and resource (list commissions) and immediately defines the domain term as 'rewards owed for referred customers' payments'. The explicit ordering ('newest first') and REST endpoint make the operation unambiguous and separable from siblings like get_commission or list_payouts.

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?

Usage is implied by the filtering affordances ('filter by affiliate or state'), but there is no explicit when-to-use guidance and no routing to alternatives such as rewardful_get_commission for a single record. Adequate but leaves the agent to infer context.

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