Price History

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

Annotations already mark the tool as read-only and non-destructive, but the description goes well beyond them: it discloses file-backed behavior, newest-first ordering, multiplier adjustment, absence behavior returning count 0, and honest degradation with specific error messages for missing pyarrow or missing recorder data. No contradiction with annotations exists.

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 long but every sentence adds essential operational detail: source type, timeframe behavior, row ordering, symbol semantics, error cases, limit constraints, and an example. It is front-loaded with the most important distinction ('not a live API call') and structured so the agent can quickly route to the right behavior.

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 output schema exists, the description does not need to explain return shapes. It covers the data source, optionality, failure modes, parameter constraints, and a concrete usage example. An agent has everything needed to invoke the tool correctly and interpret unusual outcomes like count 0.

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 carries the full burden for parameters. It explains timeframe values ('daily' vs 'raw'), the meaning and caps for limit (daily capped at 200, raw at 500), and the symbol semantics including that it is not checked against token_list and absent symbols return count 0. All three parameters are meaningfully documented.

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 this tool returns historical prices from a local recorder, not a live API call, and distinguishes the daily OHLCV and raw snapshot modes. It is unambiguous about the resource and scope, and the 'not a live API call' note separates it from quote/quotes siblings without opening their schemas.

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?

It explicitly tells the agent this is not a live API call, indicating the tool is for historical data rather than current market data. It also explains the data source is optional and may not exist, and gives error behavior. However, it does not name a sibling tool like quote as the alternative for live prices, so the when-to-use guidance is clear but not fully explicit about alternatives.

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