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

Beyond the readOnlyHint annotation, the description discloses the data source (Coinbase), a material freshness caveat (the newest candle may still be forming), the pricing model ($0.002 USDC per successful call via x402, failed calls uncharged), and a non-advice disclaimer. These are exactly the behavioral traits annotations cannot carry.

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 core purpose is front-loaded before the indicator details and caveats. It is a long, dense run-on, but nearly every clause earns its place (indicator set, source, freshness, pricing). The disclaimers and payment detail could be tightened slightly.

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?

An output schema exists, so return values need no explanation. The description nonetheless supplies everything else an agent needs to call it correctly: the computed indicator set, the candle source and granularity range, data-freshness behavior, and the billing model.

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 every parameter is already documented, and the description largely restates defaults (SMA 20/50/200, EMA 12/26) already in the schema. It adds minor value by framing limit as 'candles used for the computation' and naming the RSI/MACD/Bollinger/ATR conventions, but this is baseline territory.

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 precise verb (compute technical indicators) and resource (one crypto pair and interval), then enumerates exactly which indicators and periods it returns. This clearly separates it from crypto_candles (raw bars) and crypto_price (spot quote), even without naming a sibling.

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?

Usage is implied by the indicator list, so an agent can infer 'use this when you need technical analysis,' but there is no explicit when-to-use, when-not, or routing to alternatives like crypto_candles or crypto_price. Context is present but no guidance or exclusions.

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