render_chart

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

With no annotations, the description carries the full burden and does so well: it discloses the return contract {ok, html, chart:{...}} and names the audit fields (plot_stats, source_rows/plotted_rows/unique_entities, assumptions, advisories). It also discloses the transform_code sandbox restrictions (variables df/pd/np only, must produce `result`, no import/open/try/class), which is genuine behavioral detail. It stops short of stating failure modes or permissions, so not a 5.

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?

Front-loads the one-line purpose, then the return contract, then a clean Args block, so an agent can stop reading early. It is long, but the length is driven by a large param surface and the enumeration of chart types, so most sentences earn their place; the parenthetical asides are slightly dense.

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 16-param, annotation-free tool with no output schema, the description covers the return shape and nearly all parameters. The unaddressed `filename` parameter and the absence of error/permission behavior are the only real gaps, so it is close to but not fully complete.

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 compensate and largely does: it documents data_text, chart_type (with a full 30+ value enumeration absent from the schema), title, subtitle, axes, transform_code, annotation, theme, label_col, target, sheet, and the three header-repair params. Only `filename` is undocumented, leaving a minor gap against the 16-param surface.

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?

States a specific verb+resource+scope: 'Render one interactive ECharts HTML chart from tabular data', which is concrete and actionable. It does not differentiate itself from siblings like list_chart_types or profile_data, so an agent must infer the boundary, keeping it below a 5.

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?

There is embedded guidance ('quote ONLY these numbers in your caption', 'read them before delivering', 'convert to CSV first if using data_text'), which is useful procedural context. However, it never states when to choose this tool over list_chart_types or profile_data, so usage vs alternatives is only implied.

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