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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description adds real value beyond that by spelling out the handoff model: it returns a live quote and a prefilled link, and the remaining steps happen on the site rather than through this tool. It omits auth/KYC requirements and quote expiry, which keeps it from a 5.

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?

Three short sentences, front-loaded with the trigger ('Use when...'), followed by what is returned and what is not done. Every sentence carries distinct information with no filler.

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 does the work of disclosing the return payload (live quote, prefilled link, on-site steps), which is the key thing an agent needs. Given the openWorld annotation and the KYC/AML-flavored sibling set, missing prerequisite or quote-validity guidance is a minor gap rather than a blocker.

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 100%, so all four parameters (amount, to_code, from_code, amount_side) are already documented with defaults and enum values. The description only restates the default direction pair and the SBP QR rail; it adds no syntax or constraint detail beyond the schema, so the baseline 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 gives a concrete verb+resource: it starts/prepares a RUB-via-SBP-QR to USDT exchange order, returning a live quote and prefilled link. It is clear about the direction pair and the wallet rail, but it never names the sibling it is distinct from (calculate_exchange, find_exchange_route), leaving the agent to infer the boundary.

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?

'Use when the user wants to continue with a RUB via SBP QR (Omega Wallet) to USDT exchange' states the triggering condition, and 'Does not submit an order' carves out a clear non-action. No alternative tool is named and no prerequisites (e.g. payment passport / AML checks implied by the sibling set) are stated, so it falls short of explicit when/when-not routing.

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