get_referral_status

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

Annotations already declare readOnlyHint=true and openWorldHint=false, and the description adds genuinely useful context beyond them: credits are discounts on your own fees and never cash, and an api_key obtained from register_agent is required. It stops short of covering auth failure modes or how expiry dates are formatted/returned.

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, front-loaded sentences with no filler; the return contents come first and the clarifying constraint on credits follows. It could open with an explicit verb+resource statement rather than a bare noun list.

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 input parameters, the description carries the load and does describe the returned fields (referrer, referred agents, credits, expiry) plus the auth prerequisite. It leaves open how the api_key is actually supplied and what an empty or errored response looks like.

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 takes zero parameters, so there is no parameter semantics to document and the baseline is 4. The description still usefully explains that an api_key is needed, implying it is supplied out-of-band rather than as a parameter.

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 enumerates exactly what the tool returns - referrer, referred agents, credits and expiry dates - which pins down the resource even though the verb is only implicit in the name. It is clearly separable from payment siblings like quote_payment or verify_receipt, but never states its purpose in a single framing sentence.

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?

There is no when-to-use or when-not-to-use guidance and no named alternative among the nine siblings. The only usage-adjacent statement is the prerequisite that an api_key from register_agent is required, which is a precondition rather than selection guidance.

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