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

Annotations already declare destructiveHint=true, idempotentHint=true, readOnlyHint=false and openWorldHint=true, so the safety profile is covered. The description adds little beyond that — it restates the write nature and the reward-counting consequence but says nothing about reversibility, errors, or what response comes back.

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 tight clauses, front-loaded with the 'WRITE:' marker so the mutation nature is the first thing an agent sees. No filler or repetition of schema content.

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?

For a 3-parameter, fully documented mutation with no output schema, the description covers the state change and its consequence adequately. It omits what happens on success (return payload) and how it interacts with the similarly named confirm/unqualify operations, which keeps it short of a 5.

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?

Schema description coverage is 100%, so the schema already documents uuid, subscriber_id, and the confirm approval flag including its automation side effects. The description only adds the REST path showing how uuid and subscriber_id bind to the endpoint, which is marginal extra value.

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 and resource ('mark a referral as qualified') plus the business effect ('counts toward the referrer's rewards'), so an agent knows exactly what state change occurs. It does not distinguish itself from near-siblings like referralhero_confirm_referral or referralhero_unqualify_referral, leaving that differentiation to inference.

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?

The description gives no when-to-use guidance, no prerequisites, and never names the alternative tools (confirm_referral, unqualify_referral) an agent might confuse this with. The only approval context lives in the schema's 'confirm' parameter, not in the description.

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