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

Annotations already declare readOnly/idempotent/non-destructive; the description reinforces this and adds useful context: no account/email/ID needed, returns recorded limits and estimates rather than live quotes, and includes a prefilled swap link. This shapes expectations about side effects and response nature. No contradiction.

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 first sentence carries the main purpose and key limitation; the following sentence is a dense but purposeful list of return fields. The no-KYC/read-only coda is useful context, not padding. Slightly long but efficient.

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?

Given the output schema exists and annotations cover safety, the description adds the missing behavioral and access context (no live quote, no KYC, returned elements). It is complete for an agent to decide when to call and what to expect, though it could be more explicit about sibling routing.

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%: from/to include examples and amount includes decimal-string format. The tool description does not add parameter semantics beyond that, 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?

States a specific verb ('Check whether two coins can be swapped') and resource (a HiddenSwap pair), and explicitly notes it does not provide a live quote, distinguishing it from get_quote. The title reinforces the action. Clear and non-tautological.

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 phrase 'without asking for a live quote' tells agents this is the pre-trade feasibility check, implying get_quote is the alternative for live pricing. It does not explicitly name get_quote or search_coins as alternatives, so guidance is clear but not fully explicit.

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