indices_prices

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

Annotations are absent, so the description carries the full burden of behavioral disclosure. It implies a read-only operation by saying 'get', but it does not disclose any limitations, data format, pagination, rate limits, or what happens when no date range is provided. For a data retrieval tool with no annotations, this is insufficient.

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 a single, front-loaded sentence with zero extraneous words. It states the core purpose immediately and does not repeat schema details or add noise. This is appropriate for the simplicity of the operation.

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?

With no output schema and no annotations, the description should compensate by explaining what the returned historical data looks like (e.g., OHLCV, formatting, default time range) and any behavioral expectations. It does none of this. For a tool with four parameters and no structured output definition, this is incomplete and leaves an agent guessing about the response.

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 100%, so all four parameters (ticker, from, to, frame) have descriptions in the schema. The tool description adds no parameter-specific information beyond the schema. Per the rubric, with high schema coverage the baseline is 3, and the description does not exceed that baseline.

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 states a clear verb ('get'), a specific resource ('historical price data'), and the target ('an index'). It implicitly distinguishes itself from sibling price tools for other asset classes (stocks_prices, crypto_prices, etc.) and from indices_quote, which would provide current quotes. This is a precise and unambiguous purpose.

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 provides no guidance on when to use this tool over alternatives. It does not mention exclusions, conditions, or refer to any sibling tools. An agent has no help deciding between this and other *_prices tools beyond the explicit asset class in the tool name. This is a significant omission.

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