get_stock_candles

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

With no annotations, the description carries the full burden. It discloses the premium feature access risk and describes the return format as JSON with open, high, low, close values. This adds meaningful behavioral context beyond schema, though it does not cover error scenarios or rate limits.

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 well-structured and front-loaded with the purpose, then organized into Args and Returns sections. It is slightly verbose but every line provides needed information, such as the premium warning and parameter details.

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 complexity (4 parameters, no output schema, no annotations), the description is fairly complete: it covers purpose, all parameters, return format, and a caveat. It lacks explicit sibling differentiation and default behavior explanation, but defaults are present in the schema.

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 fully compensates by explaining all four parameters, including example symbols, supported resolution values, and time formats. This adds significant meaning beyond the bare schema.

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 the tool's function with a specific verb and resource: 'Get historical price data (candles) for a stock.' The term 'historical' and 'candles' distinguish it from sibling get_stock_price, which likely provides 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?

Usage is implied through the description of historical data, but there is no explicit guidance on when to use this tool versus alternatives like get_stock_price. The premium feature note provides a constraint but does not offer a clear 'when not to use' or point to alternatives.

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