fetch_historical_data

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It mentions returning OHLCV candles and optional date ranges but omits important traits such as max_rows limit, data ordering, handling of out-of-range dates, or whether results are inclusive of start/end dates. This is insufficient for safe tool invocation.

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 very concise, using two simple sentences. It front-loads the purpose and then lists key details. While it omits some information, the structure is efficient and easy to parse, making it appropriate for quick comprehension.

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 has 5 parameters, no output schema, and a large sibling group, the description lacks completeness. It does not mention output format, pagination, or max_rows behavior. Additionally, it fails to differentiate itself from similar data-fetching siblings, leaving the agent with gaps in understanding.

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 add meaning. It explains timeframe values and date format for start_date/end_date, which helps. However, it does not describe the 'symbol' parameter's expected format or 'max_rows' default/limit, leaving some ambiguity. The description adds value but is incomplete.

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 clearly states 'Historical OHLCV candles,' which conveys the core function of retrieving historical price data. It lists timeframe options and date format, further clarifying what data is available. However, it does not explicitly differentiate from sibling tools like fetch_live_price, though 'historical' implies non-real-time 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?

The description specifies valid timeframe values and ISO date format, providing some guidance on parameter usage. It does not, however, explain when to use this tool over siblings such as fetch_live_price or fetch_symbol_metadata, nor does it mention prerequisites or typical use cases.

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