get_referral_link

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

Annotations already cover safety (readOnlyHint=true, openWorldHint=false), so the bar is lower. The description adds real behavioral context beyond them: it returns the referral URL plus the fee discount the user will receive, and it defines the supported exchange universe and the required inputs. It omits failure behavior for unsupported exchanges, keeping it from a 5.

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?

The trigger condition is front-loaded, which is good, but the entire content is stated twice (Chinese then English) with no added information in the second pass — pure duplication. Still short overall, so not wasteful enough to drop below 3.

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?

With no output schema, the description carries the return burden and does so: it states the returned referral URL and the fee-discount information. Inputs and supported range are covered. Missing only edge-case behavior for unsupported exchanges/country codes.

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%, so 3 is the baseline. The description adds value over the schema by enumerating the supported exchange values (Binance, OKX, Gate.io), which constrains the otherwise free-form 'exchange' string, and by reinforcing that both inputs are required.

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?

Specific verb+resource: fetch a referral/rebate registration link for a named crypto exchange, with the supported exchange set (Binance, OKX, Gate.io) stated. An agent can distinguish this from cost-analysis siblings like compare_exchange_fees or calculate_savings without opening any schema.

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?

Gives an explicit trigger condition ('when the user asks for a discount registration link, referral code, or rebate link') and scopes it to 'a specific crypto exchange'. It does not name an alternative sibling or state when NOT to use it, so it stops short of a 5.

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