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

The annotations already cover read-only, idempotent, non-destructive behavior, but the description adds substantial context: it is free, changes nothing, requires a billing-scoped token, hides customer identity, and includes referral-disclosure obligations. It also explains pending versus cash-out/balance states, which goes beyond the annotations.

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?

The description front-loads the audience and then compresses many return fields and caveats into a few dense sentences. It is somewhat run-on due to the long enumeration, but the content is relevant and avoids repetition.

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?

There is no output schema, so the description must explain what comes back. It does so comprehensively: partner codes, links/messages, per-customer earnings with privacy constraints, totals, pending amounts, cash-out/balance amounts, sales targets, and program status. It also covers auth scope and cost.

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?

The tool has zero input parameters, so the baseline is 4. The schema is fully described and there are no parameters whose meaning needs clarification in the description.

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 clearly identifies the resource: partner codes, referral customers, earnings, pending amounts, cash-out/balance amounts, sales targets, and program status. It distinguishes the scope from a generic balance check by focusing on partner earnings and mentioning movement to balance, though it does not explicitly contrast itself with sibling tools.

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 establishes the audience ('For partners') and a prerequisite ('Needs a token with the billing scope'), which gives useful usage context. However, it does not explicitly say when to use this instead of get_balance or join_partner_program, and it mentions program-open status without routing the agent to join_partner_program for joining.

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