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

The annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description adds genuine beyond-annotation value with the fraud-relevant caveat that only accounts in the company's registered name are acceptable, but it omits any mention that a private_key must be supplied, which is the least obvious aspect of calling this 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?

It is short and free of filler, but structurally it is a dangling noun phrase with no main verb, so the reader must reconstruct the action being described. Length is fine; framing is not front-loaded around what the tool does.

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?

With no output schema, the description usefully enumerates what comes back, which is a real contribution for a read tool. However, for a tool whose schema exposes two undocumented required parameters including a credential, the definition is not complete enough on its own.

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 0%, so the description carries the full burden. It partly explains 'reference' as the order reference to quote, but says nothing about the required private_key or how the two parameters relate; format details like the GB-XXXXXX pattern are left entirely to the schema.

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 title ('How to pay for a request') and the description together imply that this tool retrieves the outstanding balance, the order reference, and the payee accounts. However, the description itself is a noun-phrase list of returned values rather than a verb+resource statement of what the tool does, and it never distinguishes this read tool from the sibling 'create_payment_link', which occupies adjacent ground.

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?

There is a hard constraint ('Pay only these') but no when-to-use or when-not-to-use guidance and no reference to any alternative. An agent cannot tell from this text whether to call get_payment_options before create_payment_link, instead of it, or in what sequence.

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