get_corridors

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

With no annotations, the description carries the full behavioral burden. It usefully discloses that the payload is capability-only and therefore stale/indicative rather than a binding quote, which implies a read with no side effects. However, it says nothing about authentication, rate limits, response size, or freshness, leaving notable gaps for a zero-annotation tool.

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 short sentences with no padding, and the payload contents are front-loaded ahead of the caution about quoting. The first sentence is a dense fragment rather than a full clause, which costs a little readability but not efficiency.

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 no-argument, no-output-schema listing tool the description covers the essential question: what fields come back and how much to trust them. Missing pieces are what the shape of the returned records looks like, whether the list is paginated, and whether credentials are required.

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 takes zero parameters, which is the baseline-4 case. The description adds nothing parameter-related because there is nothing to add, and the empty schema means there is no ambiguity for an agent to resolve.

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 concretely enumerates what the tool returns: which markets can pay which, whether an FX rate applies, and whether the two ends use different minor units. That makes the resource ('payment corridors' capability data) clear even though it is written as a noun-phrase fragment with no explicit verb. It does not differentiate itself from lookalike siblings such as get_supported_countries, get_supported_currencies, or get_capabilities.

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?

'Capability only: quote a specific corridor through the API before relying on it' tells the agent this is discovery/indicative data and that a separate quoting step is required before acting on it. That is real usage guidance, but it never names the alternative tool or endpoint, so the routing decision is still partly inferential.

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