yahoo_stock_history

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

With no annotations provided, the description carries the full burden. It discloses the return type (price and volume data) but does not mention data source limitations, time zone effects, or that it supports intraday intervals. It is a read-only operation, but the description does not elaborate on exactly what the returned data structure looks like, leaving some 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?

The description is concise and front-loaded with the main purpose, followed by a useful use-case sentence. There is no redundant information or filler.

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?

The tool is simple with three parameters, all explained in the schema. The description provides enough context for what the tool does and when to use it, though it lacks a detailed description of the return structure since there is no output schema. Overall, it is adequate for the tool's complexity.

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?

The schema description coverage is 100%, so the parameters (symbol, period, interval) are already fully documented. The description adds general context about 'specified time period' but does not add any details beyond the schema, earning the baseline score.

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 that the tool retrieves historical stock data from Yahoo Finance, specifying that it returns price and volume data for a time period. This distinguishes it from siblings like yahoo_stock_quote (current quotes) and yahoo_market_data (market overview).

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 gives clear context for use, such as charting, trend analysis, and performance evaluation over time. It implies when to use this tool rather than a quote tool, though it does not explicitly name alternative tools or state exclusions.

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