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

With no annotations provided, the description carries the full burden for behavioral disclosure. It only mentions source coverage for eastmoney_direct, but does not describe response format, latency, data freshness, rate limits, or differences between sources. This is a significant transparency gap for a real-time data tool.

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 very short and front-loaded, with zero wasted words. The only minor issue is a grammatical awkwardness in 'support all A,B,H shares,' but this does not undermine conciseness or structure.

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 output schema, the description should explain what the returned data looks like, but it doesn't. It also lacks details about source differences, symbol requirements, or any caveats. For a simple 2-parameter tool it's minimally adequate, but not complete enough for an agent to reliably use it.

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 input schema already provides 100% coverage of both parameters (source and symbol), so the baseline is 3. The description adds no extra parameter meaning beyond what the schema provides, such as symbol format or source-specific behavior.

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 'Get real-time stock market data,' which is a specific verb+resource combination. It adds the detail that eastmoney_direct supports all A, B, H shares, giving some scoping. However, it doesn't explicitly distinguish this tool from the many sibling quote-related tools, so it's not a perfect 5.

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's no explicit statement about when to use this tool versus alternatives. The mention of eastmoney_direct supporting A/B/H shares implies usage for Chinese stock markets, but no when-not or alternative tool is named. This is implied usage at best.

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