chart_set_type

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

With no annotations, the description carries the burden and discloses a key behavioral trait: 'SIDE EFFECTS: STATE_MUTATING (Modifies chart canvas display mode).' It also states a limitation that it accepts chart type name or numeric index, though it does not discuss persistence or error behavior.

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 front-loaded and structurally segmented with clear labels for use, side effects, and limitations. Every sentence earns its place without repetition or filler.

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?

For a single-parameter mutation tool with no output schema, the description covers purpose, usage context, side effect, and accepted input form. It is complete enough to call correctly, though it does not specify the active chart context or failure conditions.

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 coverage is 100% and the parameter description already maps every chart type to its numeric index. The description adds only that a name or numeric index is accepted, which is already implied by the schema, so it meets the baseline of 3.

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 specific verb and resource: 'Change chart candle rendering type.' It gives examples (Bars, Candles, Line, Area, Renko, HeikinAshi) and distinguishes this from sibling chart-setting tools like chart_set_symbol and chart_set_timeframe.

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 provides a WHEN TO USE section: 'Call when specific analysis requires alternate bar representations (e.g., Heikin Ashi for trend smoothing).' This gives clear context, though it does not name alternatives or when not to use it.

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