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

Annotations already declare read-only, idempotent, non-open-world, and non-destructive behavior. The description adds important behavioral context by disclosing the cost model: $0.050 USDC via HTTP 402, which is essential for invocation.

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?

A single front-loaded sentence that lists the computed metrics and payment mechanism without any waste. Every clause contributes to identifying the tool's output or invocation requirement.

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?

The tool is complex, but the output schema handles return values and the input schema fully covers parameter constraints. The description names all computed metrics and the HTTP 402 payment model, leaving only minor implicit details like warm-up length that the schema already captures.

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%, so both parameters are already fully documented in the schema. The description mentions chronological closing prices but adds no syntax or semantic detail beyond what the schema provides, making the baseline 3 appropriate.

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?

States a specific computational verb and enumerates exactly which analytics are produced (RSI-14, EMA-20/50, volatility, autocorrelation, regime), so an agent can tell precisely what the tool does. The resource is clearly the chronological closing-price series.

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 by saying it operates on chronological closing prices, but provides no explicit when-to-use guidance, no prerequisites, and no comparison to alternatives. Since its sibling tools are unrelated, there is little need for sibling differentiation, leaving usage only implied.

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