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

Annotations already declare readOnlyHint=true, openWorldHint=true and destructiveHint=false, so the safety profile is covered. The description adds real behavioral context beyond that: a switched-off service comes back as disabled and sharing it credits no referral, and the response deliberately omits price, fee and coverage. That is substantive disclosure the annotations do not carry.

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: content first, then the disabled/credit caveat, then the explicit scope exclusion. The last sentence is slightly redundant in restating the omission ('and there is none here to look up') but it usefully kills a plausible follow-up query.

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 return structure need not be spelled out, yet the description still flags the disabled-state case and the excluded fields, which are the parts of the payload an agent would otherwise misread. With safety covered by annotations and locale covered by the schema, nothing needed to call this correctly is missing.

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?

There is a single parameter and schema coverage is 100%, with the locale enum and its purpose fully documented in the schema itself. The description adds no locale-specific meaning, so this sits at the baseline where the schema does all the work.

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 resource (each service the affiliate holds) and the payload (their own referral link plus an HTML embed snippet), which is enough to separate it from the similarly named list_services and my_referrals. It never states an explicit verb such as 'returns' or 'lists', so the agent has to infer the operation from the shape of the output, but the resource and content are unambiguous.

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?

Usage is implied by the content described rather than stated: an agent can work out this is the tool to call when it needs embeddable referral links, and the note that price/fee/coverage are not returned signals it should look elsewhere for those. However, no sibling is named and no positive 'use this when...' condition or prerequisite is given.

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