forex_hist_em

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds that it returns a pandas DataFrame of historical data, which is useful, but it does not disclose rate limits, pagination, or error behavior. No contradictions with annotations.

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 well-structured with clear sections: source, URL, param, return, and rtype. It is compact and front-loaded with the main purpose. The URL and docstring-like formatting are slightly verbose but each element adds value.

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 one-parameter tool with no output schema and good annotations, the description is mostly adequate. It explains the return type and how to find valid symbols, but it doesn't clarify that it returns all available history (no date range) or describe output columns. This leaves minor ambiguity for new users.

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 schema has no description for the 'symbol' parameter, so the description carries the full burden. It explains that symbol is a code, tells how to get all valid codes via ak.forex_spot_em(), and provides an example URL with EURCNY. This goes beyond the schema and gives actionable guidance.

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 retrieves historical exchange rate data from East Money's forex market, using the phrase '历史行情数据' (historical market data). It distinguishes itself from spot-based siblings like forex_spot_em by the word '历史' and the URL example, though it doesn't explicitly name alternatives.

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 explicitly directs users to use ak.forex_spot_em() to obtain valid symbol codes, which is a useful practical guideline. However, it does not explicitly state when to use this tool versus other forex or history-related siblings, nor does it provide exclusions or alternative recommendations beyond that.

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