update_chart_data

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

Annotations contain only a title, so the description carries the full behavioral burden. It discloses that data is replaced, but it does not mention side effects, irreversibility, whether the presentation must be saved afterward, or what happens to previous chart data.

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 compact and front-loaded with a one-sentence purpose followed by an Args/Returns breakdown. Every line is informative, though the Returns line is somewhat generic.

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?

All five parameters are clearly explained, including the optional one, and the output schema covers return values so a detailed return description is unnecessary. The main gap is not stating that the shape must already be a chart or how errors are handled.

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 define all parameters, and it does. It explains 0-based indices, categories as names, series_data as dictionaries with 'name' and 'values' keys, and the optional presentation_id fallback behavior.

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 ('Replace') and resource ('existing chart data'), clearly indicating this tool modifies data in an existing chart. It is distinguishable from siblings like add_chart and format_chart_series, though it does not explicitly name them.

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 phrase 'existing chart data' implies this is for charts already in the presentation, providing some usage context. However, it does not explicitly state when to prefer this over add_chart or format_chart_series, nor does it mention preconditions like the target shape needing to be a chart.

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