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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety is covered and the bar is lower. The description still adds value by disclosing the returned payload (verified code, invite link, reward value, redemption terms), telling the agent what it gets back even without an output schema; it stops short of describing lookup-failure behavior.

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?

One sentence, verb first, with the return fields listed in a compact parallel structure. No filler, no redundancy, and the most important element (what you get for a specific company) is front-loaded.

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-parameter read-only lookup with full schema coverage and annotations, the description is nearly complete: it states the input identity and the output contents. The only gap is behavior on a company that cannot be resolved, which the agent must discover at call time.

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%, and the single parameter already documents "Company name or slug" with ten concrete examples. The description's "by name or slug" restates the schema rather than adding format or matching rules, so baseline 3 applies.

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 verb ("Get") and resource (referral code) and enumerates the returned payload: verified code, fast-track invite link, reward value, redemption terms. The phrase "for a specific company" implicitly contrasts with the list_* siblings, though no sibling is named explicitly.

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: call this when you need the referral details for one known company rather than a catalog listing. There is no explicit when-not guidance, no mention of what happens if the company is unknown, and no named alternative among list_all_referral_codes, search_referral_codes, etc.

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