get_rate_dynamics

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

With no annotations, the description carries the full burden. It discloses the core behavior of providing a current rate and a UP/DOWN direction indicator, but does not specify the output structure, how direction is calculated (e.g., vs previous close), or any edge cases like unavailable rates. This is acceptable but not rich.

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, front-loaded sentence that conveys the core functionality without any redundant or extraneous words. It earns a 5 for efficiency.

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 single-parameter read-only tool, the description covers the essential purpose and distinctive feature. However, the lack of any output schema and the absence of details on the return format slightly weaken completeness for an AI agent, leaving a 4 rather than a 5.

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?

The input schema already fully describes currency_code with examples (USD, EUR, RUB), achieving 100% coverage. The description adds no additional parameter-specific context beyond restating that it applies to a currency, so it earns the baseline score of 3.

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 states 'Get the current rate with change direction,' identifying the specific verb, resource, and unique scope (direction) that distinguishes this from sibling tools like get_currency_rate and get_all_rates. The addition of 'shows if rate went UP or DOWN' reinforces the distinguishing purpose.

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?

The description implies use when the caller needs direction information, but it does not explicitly mention alternatives or state when not to use this tool. There is no comparison to get_currency_rate for simple rate retrieval, so the usage context is only implicit, not clearly delineated.

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