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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior, so the safety profile is covered. The description adds valuable non-obvious behavior: the auth requirement and the exact outcome (a sign-in prompt on printdash.io) when called anonymously — a detail annotations cannot convey.

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?

Two sentences, no filler. The payload contents come first and the precondition comes second, which is the right order for an agent deciding whether it can call this now.

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?

An output schema exists, so the description need not document return structure; it instead summarizes the payload and adds the one behavioral fact an agent needs — the sign-in requirement. Nothing material is missing for a zero-parameter read tool.

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 the baseline is 4. The description correctly adds no parameter discussion, and there are no hidden inputs an agent could get wrong.

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 names the specific resource (referral summary) and enumerates exactly what it returns: referral code and link, counts of referred customers and orders, credit balance, and commission. This is a concrete verb+resource statement that leaves no ambiguity, and no sibling tool overlaps with it.

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 clearly states the precondition (a signed-in Printdash account) and describes the fallback behavior when that condition is unmet, which is real usage guidance. It does not explicitly route to alternatives, but no sibling offers comparable referral data, so there is little to exclude.

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