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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, covering the safety profile. The description adds that the tool optimizes for maximum discount and verifies compliance via country, but it does not disclose additional behavioral details such as live vs cached data or external network behavior. No contradiction with annotations.

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 with no wasted words. The core purpose is front-loaded, outputs are explicitly listed, and a practical instruction about the country parameter is included. Every sentence earns its place.

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 low-complexity, read-only tool with full schema coverage and an output schema, this description is largely complete. It could have explicitly contrasted itself with sibling tools like check_referral_link or inspect_exchange_link, but that omission is minor and does not block correct invocation.

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 input schema already explains both parameters, including the ISO country code for compliance and the allowed exchange names. The description adds little beyond restating the compliance purpose of the country parameter, so the baseline 3 is appropriate.

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 operation ('get the best referral/signup link'), a clear target ('a specific exchange'), and a selection criterion ('maximum fee discount'), while also listing the concrete outputs. This makes it easy to distinguish from sibling tools like check_referral_link or inspect_exchange_link.

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 context is clear: this tool is for retrieving the highest-discount referral link for an exchange, with country passed for compliance. It does not explicitly state when not to use it or name alternatives, but the intended use case is evident enough for an agent to select it correctly.

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