fear_greed

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

With no annotations, the description carries full burden for transparency. It discloses caching behavior ('Cached ~5min') and lists output components (score, label, factors, history). It does not mention rate limits or authentication, but given the tool's simplicity, 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 two sentences: the first front-loads the purpose and key components, the second adds detail. Every word earns its place; no redundancy or fluff.

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 no parameters and no output schema, the description fully covers the tool's functionality: what it returns (score, label, factors, history), caching behavior, and a pointer to an alternative tool for different use cases.

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 input schema has 0 parameters and 100% coverage. Baseline is 4. The description adds value by detailing what the output includes, which helps the agent understand the return format 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 states 'Get the Crypto Fear & Greed index' with specific components: composite 0-100 score, label, 7-factor breakdown, recent history. It distinguishes from the sibling tool 'fear_greed_monthly' by mentioning long-term trends.

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 explicitly provides an alternative: 'use fear_greed_monthly for long-term trends', guiding the agent on when to use which tool. However, it does not provide explicit when-not-to-use conditions or other context.

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