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

Annotations already cover read-only, non-destructive, non-idempotent and open-world. The description adds genuinely useful context beyond that: it is computed from Hyperliquid's public candles, costs $0.01/call via x402 or a credits key, the first 25 are free, and failed calls are free — which explains the non-idempotent hint. The sentence 'Reads or computes only and changes nothing' largely restates readOnlyHint, keeping it short of a 5.

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?

It front-loads the indicator inventory, which is what an agent needs to decide relevance, then follows with usage, pricing and a disclaimer. The pricing/disclaimer sentences are somewhat dense and could be trimmed, but nothing is wasted or buried.

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?

No output schema exists, so the description carries the return-value burden and does so by listing every computed indicator and the plain-language readings. Combined with full schema coverage and existing annotations, an agent has everything needed to call it correctly.

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 coverage is 100% and both parameters are documented in the schema. The description only adds the interval range (1m–1w) and the note that candles are closed, plus a coin=BTC example; that is marginal added meaning over the schema, so the baseline 3 applies.

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 names a specific resource (technical indicators for a Hyperliquid perpetual) and enumerates exactly what is computed: RSI 14, MACD 12/26/9, SMA/EMA sets, Bollinger 20/2 with %B, ATR 14 and realised volatility. That enumeration cleanly distinguishes it from hyperliquid_candles, which returns raw candles rather than derived indicators.

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 an intended consumer (trading agent or market dashboard) and a usage example (coin=BTC), so the purpose context is implied. But it never states when to prefer this over hyperliquid_candles or hyperliquid_market, nor any exclusions or prerequisites beyond the pricing note.

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