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

No annotations exist, so the description carries the full burden. It does disclose useful behavior: fixed source exchange, the 300-row ceiling, and oldest-first ordering. It omits rate limits, error cases, and whether 'up to 300' refers to the most recent 300 bars, leaving a real ambiguity.

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?

Two tight sentences, zero filler. The identifying attributes come first and the use cases second, so an agent can stop reading after sentence one if that is all it needs.

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 an output schema present, return shape need not be described, and the description covers source, intervals, cap and ordering. The remaining gap is the ambiguity of which 300 candles are returned (latest vs. earliest since no cursor parameter exists), which matters for backtest correctness.

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%, so the description must compensate. It does add meaning: the full interval vocabulary (1m/5m/15m/1h/6h/1d) and the limit ceiling of 300. It says nothing about the pair string format beyond the schema default, nor about limit range or invalid-value behavior.

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 resource (OHLCV candles) with the data source (Coinbase Exchange), the supported intervals, the row cap and ordering. An agent immediately knows this returns time-series price bars. It does not explicitly distinguish itself from the adjacent crypto_price_history or exchange_ticker siblings, which keeps it at 4.

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 phrase 'Use for charting, technical indicators (RSI, moving averages) and backtests' implies the appropriate use cases. However, it gives no guidance on when to prefer this over crypto_price_history or exchange_ticker, and no exclusions or prerequisites.

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