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

Annotations declare readOnlyHint=true and openWorldHint=true, and the description is consistent with those. Beyond annotations, it adds genuinely valuable behavioral disclosure: the $0.10 USDC payment via x402 on Solana or Base (an agent should know a call costs money), the rejection of invalid pairs before payment, and a concrete summary-format example. These exceed what the structured annotations convey.

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 dense but every clause earns its place: pricing is front-loaded, the indicator list is complete, the output contract is specified, and the pre-payment rejection behavior is a worthwhile caveat. It's slightly long but nothing is 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?

With no output schema present, the description compensates by detailing the return structure (per-indicator values and votes, combined signal, confidence levels, score, summary). Payment model, invalid-pair behavior, and interval default are all covered. The only gap is the lack of explicit sibling routing, which keeps it shy of a 5.

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 the schema already documents both parameters thoroughly (pair with examples and exchange order, interval with full enum). The description adds no parameter-level detail beyond that, so the baseline 3 applies — the schema carries the load and the description doesn't need to compensate.

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 uses a specific verb-plus-resource framing: six indicators for a crypto pair in one call, enumerating each indicator (Ichimoku, RSI 14, MACD 12/26/9, EMA 50/200, Bollinger Bands 20/2, OBV) and the output shape (values, votes, combined signal, confidence, score, summary). This sharply distinguishes it from single-indicator siblings like ichimoku_signal without opening their schemas.

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 rather than stated: the aggregation of six indicators conveys 'use when you want a confluence signal across multiple indicators,' but the description never names the sibling alternatives (ichimoku_signal, ichimoku_trend, price_levels) or gives explicit when-to-use vs when-not-to-use guidance. The 'Same as GET /signals/{pair}' line is API equivalence, not routing guidance.

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