sc_chart

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

With no annotations provided, the description carries full burden for behavioral disclosure. It correctly indicates this is a data retrieval operation ('Get historical chart data'), but does not explicitly state that it is read-only or non-destructive. There is no mention of authentication requirements, rate limits, or what happens if the ISIN is invalid. The description is adequate but not thorough.

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 two sentences totaling about 30 words, front-loading the main action and then providing use cases. Every sentence adds value, but the second sentence could be more specific (e.g., listing example timeframes). It is otherwise concise and well-structured.

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 moderate complexity (3 params, 1 required, output schema exists), the description is minimally complete. It explains what data is returned (OHLCV) and the identifying parameter (ISIN), but omits parameter details for timeframe and portfolio_id. The output schema presumably describes the return structure, but the description should still mention key aspects like time periods or data frequency.

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 must add meaning for all 3 parameters. It only mentions 'by ISIN' for the required isin parameter, providing no details about the 'timeframe' (e.g., valid values like '1d', '1w') or 'portfolio_id' (its purpose or when to use). The description fails to compensate for the lack of schema 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 clearly states the tool retrieves 'historical chart data (OHLCV) for a security by ISIN' from Scalable Capital, specifying the use cases of technical analysis, trend detection, and price history review. It distinguishes itself from siblings like sc_quote (likely current price) and sc_search (finding securities). A slight deduction for not clarifying that it's read-only, which is implicit but could be more explicit given the output schema.

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 mentions using it 'for technical analysis, trend detection, or price history review,' which gives context on when to invoke it. However, it does not explicitly state when not to use it (e.g., for real-time quotes vs. historical data) or mention alternatives among siblings like sc_quote for current pricing. No explicit exclusion or alternative guidance.

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