write_cells

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

No annotations are provided, so the description must carry transparency alone. It explicitly warns 'This route mutates workbook files (destructive operations)' and documents a ValueError for missing/invalid modes. It also lists return types and dispatch mapping, but does not cover side effects like overwriting existing cell data or format preservation.

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 well-structured with clear sections (Args, Returns, Raises, Notes), but it is lengthy. It contains a developer-oriented note ('Recommend adding short examples...') that adds noise for an agent. Overall, every mode description earns its place, but the length and extraneous note reduce conciseness.

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 (13 parameters, 5 modes), the description is thorough. It documents required params per mode, error conditions, return shapes, and destructive behavior. The output schema exists, so return-value details are not required, and the description still offers a high-level return type.

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 fully compensate. The comprehensive Args section explains every parameter, including mode-specific requirements and defaults (e.g., 'direction: "down" or "right" for series growth'). This adds substantial semantic meaning beyond the raw 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 clear verb+resource statement: 'Write data or operations to worksheet cells.' It then enumerates five distinct modes (single, range, series, merge, unmerge), which fully defines its scope. It is distinguishable from siblings like read_cells or clear_range due to the explicit writing focus.

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 provides mode-specific guidance, stating which parameters are required for each operation (e.g., 'single' requires cell_ref and value). It also warns that the route mutates workbook files, which is relevant context. However, it does not discuss when to prefer this tool over alternatives like formula_write or write_multi_sheet.

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