futures_fees_info

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is known. The description adds that the return type is pandas.DataFrame and includes a source URL, providing some context beyond the annotations. However, it does not disclose any additional behavioral traits such as update frequency or data limitations.

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 short and to the point, containing a title, a URL, and return type information in two lines. No unnecessary words, though the phrase '期货交易费用参照表' is repeated in the title and return description, which is mildly redundant but not harmful.

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-only, no-parameter tool, the description is fairly complete. It identifies the data source (openctp), provides a URL for details, and states the return type. The lack of an output schema is mitigated by the clarity of the 'fee reference table' concept, and the annotations cover the operational safety aspects.

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 tool has zero parameters, so the baseline is 4. The schema is empty (100% coverage), and there is nothing for the description to explain. The description appropriately focuses on the output rather than parameters.

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 that this tool provides an 'openctp 期货交易费用参照表' (openctp futures trading fee reference table) with a source URL. While it lacks an explicit verb, the resource and its purpose are unambiguous. It distinguishes from sibling tools like futures_rule or futures_settle by focusing specifically on fees.

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?

No guidance is given on when to use this tool versus alternatives. There is no mention of scenarios where this fee reference table is appropriate, nor any exclusions or comparisons to other futures-related tools. The description only states what it is, not when to select it.

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