stock_us_spot_em

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

Annotations already declare a safe read-only, idempotent, open-world operation, and the description adds one genuinely useful behavioral fact beyond them: the data is delayed 15 minutes. However it says nothing about row count, column set, or snapshot timing, so the added context is thin.

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?

Four short lines, front-loaded with source and subject, then return type and warning. The bare URL is marginally expendable but otherwise nothing is wasted.

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 no-param snapshot tool with no output schema, the description should at least hint at what fields the DataFrame carries or how large the snapshot is; instead it only names the return type and the 15-minute delay, leaving the payload opaque.

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 takes zero parameters, so the schema/description have nothing to disambiguate; the baseline for a no-parameter tool applies.

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?

States a specific subject+resource: US stock real-time quotes (美股-实时行情) from East Money, with a source URL. It is clear what the tool returns, but nothing distinguishes it from close siblings such as stock_us_famous_spot_em or stock_us_pink_spot_em.

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 statement of when to use this tool versus the many similar US-equity siblings (famous spot, pink sheet spot, hist, hist_min, valuation). Usage must be inferred entirely from the name.

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