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

With no annotations provided, the description carries the full burden of behavioral disclosure. It only reveals that the 'eastmoney_direct' source supports A/B/H shares, but it does not state what the function returns, whether there are rate limits, how errors for unsupported symbols are handled, or how the multiple sources differ in behavior beyond share coverage. Given the tool has 9 parameters and no output schema, this is a significant transparency gap.

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 two short sentences with no filler words, making it concise and front-loaded. The first sentence establishes the core purpose, and the second adds a specific data-source note. However, the second sentence is grammatically fragmented ('eastmoney_direct' support all A,B,H shares'), which slightly reduces clarity. It earns a 4 for efficiency but not a 5 due to the awkward phrasing.

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?

This tool has 9 parameters, no output schema, and no annotations, so the description needs to compensate significantly. It fails to explain return formats, the meaning of key parameters like interval_multiplier or recent_n, or the practical differences between sources. The schema alone covers syntax but not usage semantics. For a tool with this complexity, the description is severely under-specified, earning a 2.

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 covers 100% of parameters with descriptions, establishing a baseline of 3. The description adds value by clarifying that the 'source' parameter, specifically 'eastmoney_direct', supports all A/B/H shares, which is not obvious from the schema's enum list. This enriches parameter understanding beyond the structured data, warranting a 4.

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 uses a clear verb and resource: 'Get historical stock market data.' It states what the tool does without ambiguity, but it does not differentiate from sibling tools like getFullChart, getCandlesticks, or getHistoricalIndexFullChart, which also fetch historical market data. The added detail about 'eastmoney_direct' hints at a specific niche (A/B/H shares) but doesn't explicitly separate it from alternatives.

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 phrase 'eastmoney_direct support all A,B,H shares' implies a usage context — if you need data for A/B/H shares, use this source. However, the description provides no explicit 'when to use' guidance and does not mention alternative tools or scenarios where this tool should be avoided. It relies on the agent inferring usage from this single hint, which is a weak form of guidance.

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