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

Annotations only flag readOnlyHint=false, and the description is consistent with a mutation. It adds real behavior beyond annotations: the two-phase flow (rate first, then exchange) and a 0.01 minimum granularity. It does not state what happens on insufficient funds or whether the operation is reversible.

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?

A single dense sentence that front-loads the purpose and follows with the button analogy and the count caveat. No wasted clauses, though the multiple sub-clauses make it slightly crammed.

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 two-parameter mutation with no output schema and only a readOnly annotation, the description covers purpose and the preview-then-execute flow. It still leaves the exchange-rate mechanism, failure modes, and result shape unaddressed.

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 must compensate. It explains 'count — how many coins, down to 0.01' and identifies the accepted currencies, but leaves the meaning of count ambiguous (coins spent vs. coins received) and adds no rate mechanics.

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?

Names a specific verb (exchange/разменять) and precise resources: gold or silver converted into copper. No sibling tool performs currency exchange, so there is no ambiguity with the listed tools.

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?

Implies usage through the analogy to the money-panel 'Разменять' button and the note that a rate is shown before the exchange, but gives no explicit when-to-use/when-not guidance and names no alternative.

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