futures_zh_realtime

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 clear. The description adds useful behavior context by including the data source URL (Sina Finance), specifying that data is real-time, and confirming the return type as pandas.DataFrame. This goes beyond the annotations without contradicting them.

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 concise and front-loaded with the core purpose, followed by a data source URL and parameter/return documentation. However, the overall description and return line repeat nearly identical phrasing ('期货品种当前时刻所有可交易的合约实时数据'), adding slight redundancy but not significant bloat.

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?

The tool has a simple signature, annotations, and a brief description that covers purpose, parameter, and return type. However, it lacks usage context to differentiate it from several similar sibling tools (e.g., futures_zh_spot, futures_main_sina) and does not describe the output columns or any limitations. For an agent selecting among many futures tools, this is a notable gap.

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 description explicitly explains the 'symbol' parameter as a futures variety name and directs users to ak.futures_symbol_mark() for the full list of valid names. This adds meaningful value beyond the input schema, which only provides a default value (PTA) with no description. The parameter semantics are clear and actionable.

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 real-time data for all tradable contracts of a futures variety at the current moment. The verb is implied and the resource is specific ('期货品种当前时刻所有可交易的合约实时数据'). It does not explicitly distinguish itself from sibling tools like futures_zh_spot, which may also provide real-time futures quotes, so it loses one point.

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 no guidance on when to use this tool versus alternatives. It only mentions how to obtain the symbol parameter via ak.futures_symbol_mark(), which is a prerequisite rather than usage context. There are no exclusions or comparisons to other futures real-time tools, making selection ambiguous.

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