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

The annotations already cover the safety profile (readOnly, non-destructive, closed-world), so the lower bar applies. The description adds the scope of what is counted, notably the qualifier that funding-round counts are limited to those with public sources, which is behavioral detail not present in the annotations. However, it does not state the shape or key names of the response, and there is no output schema to fill that 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?

It is short and front-loaded, opening with the resource and then listing the counted entities. The same content is restated in Chinese and then English, so there is some duplication, but that bilingual structure is intentional rather than padding.

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 zero-parameter, read-only tool with no output schema, the description says why it exists and enumerates the five metrics returned, which is close to all the context an agent needs. The only remaining gap is the exact response format and key names, which an agent must discover by calling 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 tool takes zero parameters, so the baseline of 4 applies, and the description introduces no confusing parameter-like language. Nothing beyond the baseline is needed here.

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 contains a specific verb ('对外统计' / public counts) plus the resource (the SVTR AI Venture Database) and even enumerates the countable entities: AI companies, investors, people, publicly-sourced funding rounds, and original articles. That is enough to separate it from sibling profile/search tools, though it never names a sibling explicitly.

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?

Usage is only implied: an agent can infer this is the tool for headline/overview numbers, but the description contains no explicit 'use this when' statement, no ordering advice (e.g. call before search tools), and no exclusions.

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