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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the tool's safety profile is well established. The description adds useful context by specifying 'no-sign/no-submit boundary' and 'live availability', which explains that this is a read-only informational endpoint. However, this is largely consistent with the read-only annotation, and the description does not disclose additional behavioral traits such as rate limits or response structure, so a 3 is appropriate given the annotation coverage.

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 description is two sentences and front-loads the key capability in the first clause. It includes a dense list of route details that may be more than necessary, but each part conveys meaningful information about the tool's scope. It is suitably concise without sacrificing specificity, though it could be slightly tightened by moving route counts to an example or return value.

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 tool has no parameters, no output schema, and read-only annotations, the description sufficiently explains what information the tool returns: live availability, fee model, and the no-sign/no-submit boundary. An agent can confidently invoke this tool knowing it is a pre-quote capabilities lookup. The only minor gap is that it does not explicitly state the response format, but for a capabilities endpoint the description is complete enough.

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?

The tool has zero parameters and the schema is an empty object, so there are no parameter semantics to clarify. The description instead explains the data the tool exposes (routes, fees, boundary), which is the closest equivalent to parameter semantics for a no-parameter tool. This earns the baseline of 4 for zero-parameter tools.

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 clearly states the tool's purpose with a specific verb ('Read') and resource: cross-chain bridge and swap capabilities, live availability, fee model, and the no-sign/no-submit boundary. It is differentiated from the quoting flow by the phrase 'before quoting' and from other tools by naming exact routes and fee components. This is not a tautology and gives an agent a precise idea of what the tool offers.

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 description explicitly instructs to use this tool 'before quoting', which establishes a clear temporal context relative to the quote tool. It does not explicitly name alternatives or exclusions, but the 'before quoting' guidance is a concrete usage signal that helps an agent decide when to call this capability endpoint.

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