Crypto Fear & Greed index

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

No annotations exist, so the description carries the burden. It discloses that this is a paid tool with a specific cost and payment method, which is important behavioral context. It also notes there is no input, implying no side effects, though it doesn't detail data source or update frequency.

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 compact and front-loaded with the tool's purpose. The additional cost/payment section is relevant and concise. Slightly verbose with the 'PAID TOOL' block but each sentence adds necessary info.

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-input tool, the description sufficiently explains what it returns (index and label) and the cost. Without an output schema, it could elaborate more on the label values or update frequency, but it's adequate for a simple sentiment tool.

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?

There are zero parameters and the schema is empty, so the baseline is 4. The description explicitly states 'No input', which removes any ambiguity and adds clarity beyond the schema.

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 returns the Crypto Fear & Greed index (0-100) and label, and that it gauges market sentiment. This is specific and distinct from sibling tools, though it doesn't explicitly contrast with any siblings.

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 usage context is implied: it's a market sentiment gauge. However, there is no explicit guidance on when to use this tool versus alternatives like chain_tvl or token_price, or any exclusions.

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