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

Beyond the read-only and idempotent annotations, the description discloses the data source, what each measure prints, the optional Fear & Greed guest input, and the absence of any blended score. It also states that the tool is descriptive only, with no verdict, advice, or prediction.

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 front-loaded and every major element earns its place, especially because there is no output schema to explain the return shape. It is dense and contains minor repetition, such as restating that each measure prints its historical percentile, but it is not padded with irrelevant material.

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 zero-parameter tool with no output schema, the description is unusually complete: it names each measure, explains the calculation context, describes the guest field, and clarifies the output framing. An agent has enough information to select and correctly interpret the tool without additional documentation.

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 takes zero parameters, so there is no parameter semantics to explain. The baseline of 4 applies because the description does not need to compensate for any input schema gaps.

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 a specific resource: a panel of five named bitcoin cycle measures computed from the server's price record. It is clear what the tool returns, but it does not explicitly distinguish itself from siblings such as rainbow_today or rainbow_history.

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?

It gives a clear trigger: call it when the user asks where bitcoin sits in its market cycle or names one of the listed measures. It does not name alternatives or state when not to use it, so routing guidance is strong but not exhaustive.

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