get_key_rate_history

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

The text conveys the core behavior: retrieving a historical series of key-rate changes over a date period, which weakly implies a read-only operation. However, with no annotations, the description carries the full burden and does not disclose the return shape, ordering, inclusion of only change events, or any other side-effect/constraint details.

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?

The description is a single, tight sentence with no filler and the key resource is front-loaded. It could have included sibling differentiation or output details while still remaining concise, so it earns a 4 rather than a 5.

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 simple read tool with two optional, fully documented parameters, the description provides the minimal core semantics. But since there is no output schema and no annotations, and the sibling get_rate_dynamics could plausibly overlap, the description is only minimally complete for correct selection and invocation.

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 coverage is 100%, so the baseline is 3; the schema already explains both from_date and to_date with defaults. The description adds no parameter-specific meaning beyond the generic 'за период', so it does not raise the score.

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 clearly identifies the resource (the Central Bank of Russia key rate) and the scope ('за период' – over a period), while 'История изменений' conveys that it returns historical changes. This distinguishes it from current-rate and currency-related siblings, but it lacks an explicit verb such as 'returns' or 'gets', so it stops short of a 5.

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 no explicit guidance on when to use this tool versus siblings like get_key_rate or get_rate_dynamics. 'За период' only implies temporal filtering; it does not state exclusions, alternatives, or conditions under which another tool should be chosen.

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