update_chart_data

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

With no annotations provided, the description carries the full burden of behavioral disclosure, and it delivers thoroughly. It discloses that the embedded workbook, literal caches, and range formulas are rewritten together, that formatting is preserved, that an auto-backup is made, that backup=False only skips rotation, that saves are atomic and validated, and that the tool refuses documents open in Word.

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 dense but every clause earns its place: core action first, then parameter semantics, then refusal conditions, then backup and safety behavior. The use of colons and semicolons packs substantial detail without filler or repetition.

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 tool's complexity, the description is complete: it covers supported chart types, data constraints, series-count restrictions, refusal reasons, backup behavior, formatting preservation, and the Word-open refusal. Since an output schema exists, not detailing return values is acceptable.

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 it does. It clarifies that data must match add_chart's shapes and must preserve the series COUNT, explains series_names as renames, identifies chart_index as coming from list_charts, and explains the backup parameter's precise semantics. This adds essential meaning beyond the generic anyOf 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 opens with a precise verb and resource: 'Replace the data of an existing bar/column/line/pie/scatter chart in place.' It clearly distinguishes this from adding a new chart and ties chart_index to list_charts, making it easy for an agent to know exactly what operation this tool performs.

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 gives strong contextual guidance: it tells the agent the chart must already exist, the index comes from list_charts, data shapes mirror add_chart, and it enumerates refusal conditions (combo, 3D, series-count changes, ragged data, documents open in Word). However, it does not explicitly state 'use add_chart for new charts' or name an alternative for unsupported cases, so the routing guidance is strong but slightly implicit.

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