get_candles

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

With no annotations, the description carries the full burden and adds meaningful behavioral detail: it discloses the return order (oldest-first), the exact fields (time/open/high/low/close/volume), and how to interpret the timeframe parameter. It doesn't cover edge cases like current forming candles or rate limits, but this is a solid disclosure for a simple read 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?

The description is concise and front-loaded: the first sentence states the tool's purpose, followed by two sentences that add essential detail without waste. Every sentence earns its place, and the formatting of the timeframe mappings is easy to scan.

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?

Given the tool's simplicity (3 params, no output schema, no annotations), the description covers purpose, timeframe semantics, output format, and a usage note. It omits count-related behavior and any explicit alternatives, but it is sufficiently complete for an agent to invoke this tool effectively in most cases.

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 0%, so the description must compensate. It explains the timeframe parameter with a helpful mapping (60=M1, 300=M5, etc.), but it does not explain the 'count' parameter or its default behavior. Asset is self-explanatory. Partial compensation for the key parameter but not all.

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 starts with 'Fetch OHLCV candles for analysis,' which clearly states the verb (fetch), resource (OHLCV candles), and intended purpose (analysis). This distinguishes it from siblings like get_price, which likely returns current price data.

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 provides a clear usage hint: 'Call this for several timeframes to analyse multiple horizons at once.' While it doesn't explicitly name alternatives or when-not-to-use, the context implies this is the tool for historical candle data versus price snapshots.

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