fund_fee_em

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

Annotations already declare the tool as read-only, open-world, idempotent, and non-destructive, so the description does not need to repeat that. The description adds the source URL and the fact that the return is a pandas DataFrame containing trading rules, which is useful context. However, it does not disclose error handling, network dependencies, or any side effects, which would be extra value beyond the 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 efficiently structured using a standard docstring format: title, source URL, parameter docs, and return docs. Each line serves a purpose without fluff, making it easy to scan. It is concise yet complete for the information it conveys.

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?

With only two parameters and no output schema, the description adequately covers both inputs and states that the return is a DataFrame of trading rules. However, it does not explain the default symbol value or give an idea of the DataFrame's columns, leaving some ambiguity about the exact output structure. Still, it is sufficient for an agent to invoke the tool and interpret the basic result.

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 provides no descriptions (coverage 0%), so the description carries the full burden. It clearly documents both parameters: symbol as the fund code, and indicator with an explicit enumeration of valid Chinese labels (e.g., '交易状态', '申购费率（前端）'). This fully compensates for the schema's lack of detail and gives the agent precise input semantics.

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 this tool provides fund purchase information (购买信息) from a fund profile, with a specific source URL and a return type of trading rules. It lists the exact scope via the indicator parameter, but does not explicitly differentiate it from sibling tools like fund_purchase_em, so it misses the distinctiveness bonus.

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 other fund-related tools, nor does it mention any exclusions or alternative tools. It simply lists parameters and their types, leaving the agent to infer usage from the name and parameter names.

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