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

Annotations already declare readOnlyHint and openWorldHint=false; the description adds genuinely new context by stating the call is unsigned, free, and will not reveal a route or a saving. That last clause sets expectations about what the tool deliberately withholds, which an agent could otherwise misread. No contradiction with the read-only annotation.

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 densely packed sentence with the imperative call-first guidance front-loaded, followed by the enumeration of what is returned. Every clause carries information, though the final 'never reveals a route or a saving' clause is easy to misparse and could be split out.

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?

There is no output schema, so the description must carry the return shape; it does list four things the caller learns, which is helpful. However, it never says what the result looks like when a corridor is unsupported, nor clarifies the route/saving withholding behavior in terms of actual output, leaving gaps for a four-required-parameter preflight tool.

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 only 50%: source_asset and source_network have format hints, but destination_asset and destination_network are undocumented. The description never mentions any parameter, format convention, or that source/destination must form a supported corridor, so it does not compensate for the coverage gap.

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 the check concretely: corridor coverage, the routes compared, the route the caller may declare, and the contracts a route touches. It distinguishes itself from write-oriented siblings like recta_prepare_signed_request by being a coverage/fit check. The phrase 'which route you can declare as yours' is slightly abstract but the overall purpose is unmistakable.

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?

It gives explicit ordering guidance: 'Call first, before a cross-chain stablecoin or BTC transfer', which tells the agent this is a preflight step ahead of the signed/prepare siblings. It does not name alternatives such as recta_saving_odds or recta_prepare_signed_request, nor state when not to use it, so it stops short of full routing guidance.

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