price_chart

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

Annotations already declare readOnlyHint/openWorldHint, and the description adds the critical specifics: output is ALWAYS an SVG, a file is written with the path surfaced in `savedTo`, and the user's own browser is opened to the Stockbit chart unless skipped. It explicitly states annotations are render-only and 'nothing is written to the Stockbit account,' which reinforces readOnlyHint rather than contradicting it — annotation_contradiction is false.

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?

Four sentences, each carrying a distinct concern: chart composition, output/file behavior, annotation semantics, and the browser side effect. The core purpose and key constraints are front-loaded ('ALWAYS rendered as an SVG'), and there is no redundant or filler prose.

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?

Despite 13 parameters and no output schema, the description explains what would otherwise be opaque: the return shape (image plus `savedTo` path plus `stockbitUrl`), the always-SVG guarantee, and the side-effect boundary. Defaults like dark theme and sma20+sma50 overlays are left to the schema, which documents them at 100% coverage, so nothing needed to call the tool correctly is missing.

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%, so the baseline is 3. The description earns above-baseline by adding semantics the schema lacks for the two trickiest params: `annotations` is explained as render-only evidence-drawing (levels, zones, trend lines, markers) and `open_in_stockbit`'s default browser-opening behavior plus skip flag is clarified. Remaining params (bars, from, to, theme) correctly lean on the fully-covered schema.

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-resource pair: renders a candlestick chart for an IDX stock as an SVG, and enumerates its content (daily candles, volume, overlays, sub-panels, support/resistance). It explicitly differentiates from the technicals sibling — 'Use technicals for the numbers; this is the picture' — so an agent can select it without opening 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?

Provides explicit when-to-use guidance by naming the alternative (`technicals`) for numeric data, and frames the annotations param as the intended mechanism 'to show the evidence behind an analysis.' It also discloses the default browser-opening side effect and the exact opt-out (`open_in_stockbit: false`), leaving no invocation ambiguity.

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