index_global_spot_em

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

Annotations already declare readOnlyHint=true, destructiveHint=false, and idempotentHint=true, so the safety profile is covered. The description adds the data source URL and return type (pandas.DataFrame), providing some context beyond the annotations, but does not disclose other behavioral traits like update frequency or coverage of specific indices.

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 main purpose. It includes the source URL and return type in a structured docstring-like format, with no redundant or irrelevant content.

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 no parameters and no output schema, the description adequately communicates that the tool returns a pandas DataFrame of real-time global index quotes. It names the data source and the specific data category, which is sufficient for a simple read-only tool. Additional column details or index coverage would be nice but are not critical for the tool's straightforward purpose.

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 and the schema coverage is 100% (empty schema), so there are no parameter semantics to explain. The description's mention of the return type adds value, and the baseline of 4 for no-parameter tools is appropriate.

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 identifies the tool as providing real-time global index quotes from Eastmoney, with the specific resource (global indices) and data type (spot/real-time). It distinguishes itself from siblings like index_global_hist_em (historical) through the explicit '实时行情' (real-time) label, though it lacks an explicit verb like 'retrieve'.

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?

There is no guidance on when to use this tool versus alternatives. It does not mention that this is for real-time spot data while historical data would come from index_global_hist_em, nor does it reference any other related tools. The name implies real-time, but the description does not explicitly state usage context.

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