fetch_prices

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

Discloses API with yfinance fallback, environment variable dependencies, and return format. No annotations provided, so description carries full burden; misses potential error scenarios.

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?

Well-structured, front-loaded with purpose, then API details, environment variables, parameters, and return format. Every sentence is informative and concise.

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?

Comprehensive coverage: purpose, configuration, parameters, return format. Given an output schema exists, the description is sufficient 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?

With 0% schema description coverage, the description compensates fully by detailing each parameter's format, defaults, and source options, adding significant meaning.

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?

Clearly states it fetches historical daily OHLCV prices for given tickers. Distinguishes from sibling tools like fetch_financials and fetch_ff_factors.

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?

Provides context on when to use the tool for historical price data, explains fallback behavior and environment variable configuration. Lacks explicit when-not-to-use but is otherwise clear.

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