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

The description mentions that it returns aggregated text (总量/生产型/销售型/依赖型) and explicitly states what is not included (other categories, list details). With openWorldHint=true, the agent knows results may vary, but the description does not elaborate on limitations like data freshness or exact definition of '近两年', which is a 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 concise and structured with sections for the query scope, included/excluded metrics, and examples, making it easy to scan. The pricing info is extra but not overly verbose; it doesn't detract from readability.

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 count tool with an output schema and clear parameters, the description sufficiently explains the aggregation logic and examples. It could benefit from noting how the output is formatted (e.g., raw JSON vs. text), but the output schema likely covers that, and the tool is relatively simple.

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 all three parameters with descriptions, and the description adds context on how region and chain_name are used (e.g., hierarchical region names like '北京市海淀区'). However, it doesn't explain the 'year' parameter's role beyond being optional, and the coverage is high, so baseline 3 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 states the tool queries the count of companies with external financing in the last two years, filtered by region and industry chain, and returns aggregated totals split by type. It distinguishes itself from siblings by specifying 'invested' (companies receiving investment) and the aggregation format, though it doesn't explicitly name 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 description provides typical question examples that clarify when to use this tool, such as querying counts of companies with external financing by region and chain. It does not explicitly state when not to use it, but the examples and scope (aggregated counts, excluding lists) imply its use case.

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