获取恐惧贪婪指数

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

With no annotations, the description carries the full transparency burden. It explains the meaning of the scale ('0为极度恐惧，100为极度贪婪'), which is valuable context not present in the schema. However, it does not disclose the return format (e.g., whether it returns a single number or an object) or update frequency, but for a simple fetch tool this is adequate.

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 a single concise sentence that front-loads the action ('获取') and the resource ('恐惧贪婪指数'), then adds the scale explanation. No wasted words or unnecessary detail.

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-parameter, no-output-schema tool, the description is largely complete: it specifies the market (cryptocurrency), the index name, and the 0-100 scale. It lacks an explicit statement of the return format or update frequency, but these are not critical for a tool of this simplicity.

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 has zero parameters, so the schema is trivially fully covered. The baseline for 0 parameters is 4, and the description adds meaning by explaining the index range and interpretation, which is useful for interpreting the result.

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 it '获取加密货币市场恐惧贪婪指数' (retrieves the cryptocurrency market fear and greed index) with a specific 0-100 scale. The resource is distinct from sibling tools like crypto_sentiment_metrics, as it names a specific index rather than a general sentiment metric.

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 no explicit guidance on when to use this tool versus alternatives. It only explains what the index measures, leaving the agent to infer usage from the tool name and context. No exclusions or alternative tools are mentioned.

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