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

readOnlyHint=true already establishes a safe read, but the description adds real behavioral detail beyond annotations: default sort order (newest first), the enumerated payout states, and the ability to expand nested affiliate/commission objects. It omits pagination defaults and result-size behavior, but those are covered by the schema.

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 paragraph that is well front-loaded: what it is, ordering, returned fields, filters, and the underlying API endpoint. Every clause carries information, though the trailing 'Rewardful: GET /v1/payouts' is marginally useful for an agent that cannot make raw HTTP calls.

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 and no nested object docs, the description usefully previews the return shape (amount, currency, state) and the default ordering, which an agent needs to interpret results. Pagination semantics are left entirely to the schema, which is reasonable given its full coverage.

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 (page, limit, state, expand, affiliate_id) is already documented in the schema. The description restates the state and expand filters but adds no syntax, format, or default value beyond what the schema provides, 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?

States a specific verb and resource ('List payouts') and immediately defines the domain term ('bundles of an affiliate's payable commissions'), which distinguishes it from rewardful_get_payout and rewardful_list_commissions without opening a schema. Ordering ('newest first') and returned fields (amount, currency, state) are stated up front.

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?

Tells the agent when to reach for filtering by affiliate or state and when to use expansion ('expand affiliate or commissions'), which is genuine usage context. It never names the sibling it competes with (rewardful_get_payout for a single record) or states exclusions, so it stops short of full routing guidance.

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