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

With no annotations, the description carries the full burden. It does disclose two meaningful traits: the endpoint path and the pay-per-call cost ($0.005 USDC), which is important given payment-related siblings. However, it omits rate limits, ordering/pagination of returned candles, and any auth/payment-mechanics detail.

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?

Dense and front-loaded: the resource and return shape come first, then optional params, then endpoint and cost. The '-> /x/crypto/ohlcv/:symbol' fragment is terse but conveys the endpoint without waste.

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 explains the returned row structure, which compensates somewhat. But for a no-annotation, pay-per-call tool it still leaves out ordering, how many candles are returned by default, and payment/auth mechanics.

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 symbol, interval (with enum), and limit. The description restates the interval set and limit cap, adding no syntax or semantics beyond the structured fields, so 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 verb+resource ('OHLCV candle history for a crypto coin') and even specifies the row shape [openTime, open, high, low, close, volume], which clearly separates it from siblings like crypto_price or crypto_indicators. It does not explicitly name those siblings, so it stops short of a 5.

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?

There is no statement of when to use this tool versus crypto_price, crypto_indicators, or snapshot, and no exclusions or prerequisites beyond an implied 'you want candle history'. The pay-per-call note is a cost caveat, not usage routing.

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