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

Annotations already declare this read-only and idempotent, so the bar is lower, and the description still adds real behavioral context: the partner code is stored in the client's browser for 60 days, and the client both checks and pays on the same page. It does not describe the response shape, but for a link-generating tool that is a minor omission.

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, front-loaded with the core artifact (the partner link), followed by tracking behavior and the optional parameter's effect. No filler and nothing buried.

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 one-optional-parameter, non-destructive tool with no output schema, the description covers what is produced, its tracking lifetime, and the parameter's effect. The only gap is an explicit statement that the return value is a URL, which is implied rather than stated.

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 coverage is 100% and the schema already lists example slugs, so the schema carries the basic meaning. The description adds value beyond it by explaining the effect of supplying a service: the link then surfaces that service's price and the partner's share, which the schema does not convey.

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 a specific resource – a partner referral link to the AIfa Works accessibility page – and explains what the link does for the client (free check, then paid service on the same page). It is clearly distinct from siblings like partner_kit or plans. The only shortfall is that the producing verb ('generate', 'get') is implicit in the noun phrase.

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 client-facing context ('the client runs a free check... and pays') implies when to use it, and 'optionally name a service' gives a secondary usage mode. However, it never states when not to use it, nor points to an alternative sibling such as partner_kit, leaving routing to inference.

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