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

With no annotations, the description carries the full behavioral burden and does so richly: it discloses the cost ($0.01 USDC), the payment protocols (x402 on Base, MPP on Tempo), that the server holds no wallet and never pays, and that it returns 402 payment requirements plus a retry URL. This is exactly the kind of auth/payment context an agent needs and could not infer from the schema.

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?

Purpose is front-loaded in the opening sentence and the field list, with the payment mechanics following. There is mild redundancy — the rhetorical opener partially restates the enumerated content that follows, and the URL is repeated — but every sentence still conveys actionable information.

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?

Despite having no output schema and no annotations, the description effectively documents the return shape (every fact carries source URL, retrieval date, quote and confidence) and the complete payment handshake. An agent has everything needed to attempt the call and handle the 402 response.

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?

There is only one parameter and schema description coverage is 100%, with the schema already explaining 'Provider id from search_providers, e.g. circle'. The description adds no syntax or format detail for the id beyond confirming the single-provider scope, so the baseline of 3 applies.

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 states a specific verb and resource — retrieve the full cited record for a single provider — and enumerates the content covered (rails, corridors, licences, fees, coverage, payment support). It distinguishes itself from search_providers only implicitly via the schema hint ('Provider id from search_providers'), so the sibling contrast is not spelled out in the prose itself.

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 a clear procedural path: this is a paid endpoint, the server returns HTTP 402 requirements, and the caller must pay with their own x402/MPP client and retry the URL. It doesn't explicitly say when to prefer this over search_providers (e.g., single-record lookup vs discovery), so the when-to-use guidance is contextual rather than explicit.

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