yahoo_finance_ticker_history

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

With no annotations, the description must fully disclose behavior. It only mentions 'Returns normalized OHLCV points' without explaining what 'normalized' means, how data is truncated, or if there are rate limits. The behavior around parameter precedence (period vs start/end) is implied but not clarified.

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 sentences with no extraneous words. The first sentence provides the core purpose, the second adds usage constraint. Every word serves a purpose.

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 11 parameters, no output schema, and no annotations, the description is insufficient. It does not explain default interval, the meaning of 'normalized', or how to specify multiple symbols. The description is too brief for the complexity of the tool.

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 100% with descriptions for all 11 parameters. The description adds minimal value beyond the schema, only noting 'Use either period or start/end'. This is a baseline score of 3.

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 'Yahoo Finance historical prices' and 'Returns normalized OHLCV points for a symbol', which is a specific verb-resource pair. It distinguishes from sibling tools like yahoo_finance_ticker_quote (current price) and yahoo_finance_download (raw data) by focusing on normalized historical 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 includes 'Use either period or start/end', which provides some guidance on parameter selection but does not explicitly state when to use this tool over alternatives like yahoo_finance_ticker_quote or yahoo_finance_ticker_dividends. No exclusions are mentioned.

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