render

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

With no annotations provided, the description fully discloses behavioral traits: it is a paid feature, fetches data locally but sends a numeric slice to the API, returns a PNG and saves it to a file, and mentions the saved path in the text result. This goes beyond what the structured fields offer and provides transparency about side effects and authentication.

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, focused paragraph of four sentences. Each sentence adds value: purpose, cost/auth, data handling, output, and usage tips. It is front-loaded with the main action and avoids redundancy. 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?

Given the complexity (15 parameters, nested objects, no output schema), the description provides a high-level overview but misses details. It explains the main output and file-saving but does not cover `risk`, `markers`, `style`, `session`, `timezone`, or other schema properties. The return format is partially described, but the 'text result' for the path is vague. Additional details would be needed for full completeness.

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% and the description only mentions three parameters (`save_path`, `format`, `include_base64`) in passing. The other 12 parameters (e.g., `symbol`, `start`, `timeframe`, `style`) are not explained. The description does not compensate for the lack of schema documentation, leaving agents with incomplete guidance for parameter usage.

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 'Render a candlestick chart image of a trade' with a specific verb and resource. It distinguishes itself from sibling tools (resolve_symbol, get_price_context, analyze) by focusing on chart rendering. Additional details about output format and saving file reinforce the 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 mentions a prerequisite ('needs TRADE_ANALYTICS_API_KEY') and gives usage tips like using `save_path`, `format:'svg'`, and `include_base64:true`. It implicitly suggests when to use (for charting) but does not explicitly state when not to use or compare to siblings. The context is clear but exclusions are absent.

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