get_historical_data

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

With no annotations, the description carries the full burden of behavioral disclosure. It mentions the subscription requirement, which is helpful, but does not explicitly discuss read-only nature, potential errors, rate limits, or pagination. The output schema exists, so return format is covered, but behavioral edge cases are under-specified.

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 compact: one clear purpose sentence followed by a structured parameter list with no fluff. The most important information is front-loaded, and every sentence earns its place.

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 description covers all parameters and the subscription requirement, and an output schema exists. However, it omits details like timezone handling and whether date ranges are inclusive, leaving minor gaps for a data-fetch 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 description coverage is 0%, yet the description lists all five parameters with formats and allowed values, e.g., interval options ('ONE_MINUTE', 'FIVE_MINUTE', etc.) and date format (YYYY-MM-DD). This fully compensates for the schema's lack of descriptions.

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 opens with 'Fetch historical daily/intraday OHLCV candles', clearly stating the action and resource. This distinguishes it from sibling tools like get_option_chain or get_market_context, making the tool's purpose unambiguous.

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 notes 'Requires Plan B subscription', providing a clear prerequisite, but it does not explicitly mention when to prefer this over alternatives like get_batch_market_context. Usage context is implied by the tool name and description, but explicit when-to-use/when-not-to-use guidance is missing.

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