Crypto Fear & Greed index

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

No annotations provided, but description discloses that it is a read-only tool with no input, and importantly mentions it is a paid tool with cost details (up to $0.005 USDC per call). This adds behavioral context beyond just stating it's a read operation.

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?

Two sentences plus pricing information, all front-loaded. Every sentence provides essential information with zero waste.

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?

Given zero parameters, no output schema, and no annotations, the description fully informs the agent: what it returns (index and label), how to use it (gauge sentiment), and cost. No gaps.

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?

No parameters exist, and schema coverage is 100%. Description adds value by confirming 'No input', which helps the agent understand that no parameters are needed. Baseline for zero params is 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?

Description clearly states it returns the Crypto Fear & Greed index (0-100) and its label, with a clear purpose to gauge market sentiment. It distinguishes itself from sibling tools, as no other sentiment index tool is present.

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?

Explicitly says 'Use to gauge overall market sentiment', providing clear context. No exclusions or alternatives mentioned, but sibling tools are diverse and none directly compete, so minimal guidance needed.

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