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

With no annotations, the description carries the full burden and mostly delivers: it discloses the free-tier constraint, a 15-minute refresh cadence (data staleness), the hard symbol coverage limit (BTC/ETH only), and the exact return shape. It does not mention auth requirements, rate limits, or what happens when data is unavailable for a symbol, so it falls short of fully transparent for an unannotated tool.

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?

Purpose is front-loaded in the opening clause, the return shape is stated compactly, and the routing/pricing sentence closes it out. Dense but waste-free — the price tags on siblings exist to support the selection decision, not as 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?

For a 1-param, no-output-schema tool, the description compensation for the missing output schema by naming the returned fields ({price, regime, nearestSupport, nearestResistance}) is the key win. Remaining gaps are minor: no mention of error/empty behavior or rate limits on a free tier.

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 0%, but the single parameter has an enum of BTC/ETH that is self-documenting. The description reinforces the constraint ('for BTC and ETH only') and tells the agent where to go for other symbols, which adds useful routing meaning beyond the enum itself.

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 ('get_free_snapshot') and spells out exactly what it returns: market regime (trend, volatility, RSI, ATR%) plus nearest support/resistance, scoped to BTC/ETH. It explicitly names the siblings it is not (get_signal_bias, get_trade_plan, get_market_regime, get_support_resistance), so an agent can separate it without opening any schema.

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 an explicit selection rule ('pick this over the paid siblings when you just need a quick read on BTC/ETH'), then routes each other need to the right alternative with its price and capability boundary. Both when-to-use and when-not-to-use are stated, with named alternatives for each case.

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