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

No annotations are provided, so the description carries the full burden. It discloses that the data is end-of-day and historical, which is useful, but it does not explain what 'light' means (e.g., limited fields or data points), nor does it mention response format, pagination, or any limitations. This is a significant gap for a tool with no other behavioral documentation.

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 two sentences, front-loaded with the core action, and every sentence adds context. No fluff or repetition of the tool name.

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?

There is no output schema, so the description should explain what the tool returns; it does not. While it gives enough to invoke correctly (symbol with optional dates), it lacks details on response structure, the 'light' vs 'full' distinction, or any limits. For a moderately simple tool, this is adequate but with clear gaps.

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%, with clear descriptions for all three parameters including a symbol example and date formats. The description adds no additional parameter meaning beyond what the schema provides, so it meets the baseline but does not compensate further.

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 the tool accesses historical end-of-day forex prices, which distinguishes it from intraday sibling tools like getForex1MinuteData and getForex5MinuteData. However, it does not explicitly contrast with getForexHistoricalFullChart, relying on the 'light' naming to imply the difference.

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 provides clear context: use for long-term price trends and end-of-day analysis. It does not explicitly exclude alternatives or name when not to use it, but the use case is well implied for a historical daily data tool.

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