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

readOnlyHint=true is consistent with 'Read', so no contradiction. The description adds useful content scope (availability, terms, commission offer), which goes beyond the annotation, but says nothing about caching, freshness, or what an unregistered/eligible-vs-not result means.

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 front-loaded sentence with no waste. The resource and payload are stated immediately.

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 parameters, no output schema, and a readOnly annotation, this is close to sufficient: it tells the agent what information comes back. Minor gap is the missing relationship to sibling referral_* reads.

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?

Zero input parameters, so the baseline of 4 applies. There is nothing for the description to disambiguate on the parameter side.

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 (Read) and resource (Mekler referral availability, terms and commission offer). It is distinguishable from mutating siblings like referral_accept_terms and referral_register, though it partially overlaps with referral_status and doesn't clarify the boundary.

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?

No explicit when-to-use guidance or alternatives are given. 'Current' implies a freshness-sensitive informational read, but the description never says when to prefer this over referral_status or referral_notices.

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