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

Annotations already carry the safety profile (idempotentHint=true, destructiveHint=false), and the description adds useful program behavior: friends start Free with no card, both sides get credit on first paid subscription. However, it never addresses why readOnlyHint=false for a 'get' tool (i.e., what side effect link generation may have), which is the one behavior an agent would want clarified.

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?

Four short sentences, front-loaded with what the tool returns before explaining program terms and the quoting instruction. Slightly longer than strictly necessary for a no-arg call, but each sentence carries distinct information.

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 must cover the return, and it does call out the rewards field and its trial terms plus statistics. It leaves the link field itself and the shape of the statistics undocumented, so coverage is good but not exhaustive.

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 nothing for the description to disambiguate; baseline 4 applies. The description instead spends its words on the response's rewards field, which is reasonable given no parameters exist.

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 gives a specific verb+resource ('Get your Convika referral link') plus the secondary payload ('your referral statistics'), which is enough to separate it from analytics/site tools. It does not, however, explicitly differentiate itself from other get_* siblings like get_site or get_domain_status beyond the unique resource name.

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 clear context — this is for sharing a link with friends to earn credit — and explicitly cross-references create_claim_code as reporting the same trial terms, which helps an agent route between the two. There is no explicit when-not or exclusion statement.

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