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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds genuinely useful behavioral context beyond that: it operates on *closed* candles (implying no live intrabar values), it returns only the three headline verdicts rather than raw indicator numbers, and the richer data lives behind paid x402 routes. It stops short of stating latency, rate limits, or caching behavior for the free tier.

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?

Three sentences, front-loaded with the actual capability before the commercial tier explanation. The paid-route sentence is informative for routing rather than pure marketing, but it consumes a meaningful share of the text and could be tighter.

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, the description usefully tells the agent what comes back — a categorical bias range, a trend label and a regime label — which is enough to use the result without parsing surprises. It does not describe the response envelope, units or whether confidence/score fields accompany the labels, leaving a small gap.

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% with per-parameter descriptions and an enum on timeframe, so the schema already carries the semantics. The description adds only the framing that the read applies to a crypto asset on closed candles; it does not clarify symbol resolution rules or the default timeframe, which remain in the schema. Baseline 3 is 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 verb and resource ('descriptive technical read for a crypto asset') and enumerates exactly what is produced: bias, trend and regime, plus the indicators consumed (RSI, MACD, EMA 20/50/200, Bollinger, ADX). It also clearly scopes itself as the free preview tier versus the paid x402 routes, so an agent knows precisely which capability it is selecting.

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 gives a clear context of use (closed 15m/1h/4h/1d candles) and implicitly routes the agent: use this for the free bias/trend/regime summary, use the paid /v1/lite, /v1/risk, /v1/backtest routes when indicator values, VaR/CVaR, drawdowns, ATR sizing or backtests are needed. There are no sibling tools to exclude, but explicit 'when not to use' language is absent beyond the tier comparison.

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