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

With no annotations, the description carries the full burden and does so well: 15-minute refresh cadence, data age disclosed in every response, read-only 'descriptive data' framing, and detailed payment behavior (x402, $0.01 USDC on Base, automatic payment challenge with retry semantics). These are exactly the non-obvious operational facts an agent needs.

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?

Front-loaded with the resource and symbol scope, then progressively adds metric list, usage note, freshness, and payment. Dense but every sentence carries information; the 'not financial advice' clause is the only near-filler.

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?

There is no output schema, so the description compensates by enumerating the returned fields (mark/index price, funding rate, OI change, taker buy share, per-timeframe EMA/RSI/ATR, prior 20-bar high/low). Payment, freshness, and symbol scope are all covered, leaving no material gap for invocation.

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 an enum and an inline default, so the schema already documents the only parameter, including the ALL value. The description adds only the implicit notion of multi-symbol coverage in one call, which is marginal. 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 states a specific verb-scope-resource combination: multi-timeframe market state for a named list of perpetual futures symbols returned in one call, then enumerates the metrics returned. It is unmistakable against siblings (bsc_alerts, event_facts, ping), which cover unrelated domains.

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 names the target consumer and context — 'trading agents needing clean market context' — which tells the agent when this is the right call. It does not name any alternative or when-not-to-use condition, so it stops short of a 5.

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