Crypto Fear & Greed Index

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

Annotations already indicate read-only, idempotent, non-destructive behavior. The description adds value by explaining the output structure (index value plus history) and the meaning of the numeric range. This is consistent with annotations and provides useful context beyond the structured data.

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?

One sentence, front-loaded with key information (market sentiment index and range), no redundancy. Every word earns its place.

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 simple read-only tool with one parameter and no output schema, the description fully explains what the tool returns (latest value plus history) and how the parameter affects output. No gaps remain.

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?

Schema description coverage is 100%, with the 'limit' parameter described as 'Number of days of history (1 = today only)'. The tool description reinforces this but does not add new meaning. Baseline score of 3 is appropriate given high schema coverage.

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's a 'Crypto market sentiment index' with explicit range (0-100) and specifies it returns 'the latest value plus history'. This precisely identifies the tool's purpose and distinguishes it from sibling tools like crypto_candles (price data) or crypto_ticker (current ticker).

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 implies usage for market sentiment, but does not explicitly provide when-to-use or when-not-to-use guidance. No alternatives are mentioned, though the unique nature of the tool among siblings reduces the need for exclusion criteria.

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