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

Annotations already declare readOnlyHint=false, destructiveHint=false, idempotentHint=false, and openWorldHint=true, so the safety and mutation profile is covered. The description adds that the payload may contain formulas, but it does not state overwrite behavior for existing cells, sheet-creation rules, or error/return behavior, leaving meaningful operational details undisclosed.

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?

A single front-loaded sentence with no redundant wording; it states the essential action and target immediately.

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 relatively simple write tool with full schema coverage and safety annotations, the description is adequate but omits important invocation context such as whether existing cells are overwritten, whether a missing worksheet is created, and what the tool returns.

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%, establishing a baseline of 3; the description goes slightly beyond the schema by stating that values may be formulas as well as cell values, which clarifies the accepted content of the required values parameter.

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 gives a specific verb ('Write'), resource ('2D array of cell values or formulas'), and target ('a worksheet in an Excel (.xlsx) workbook'), which clearly differentiates it from read-oriented siblings like excel_read_sheet.

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?

It implies the use case (writing values/formulas to a sheet) but offers no explicit when-to-use or when-not-to-use guidance, nor does it name alternatives such as excel_read_sheet or excel_copy_sheet. The verb makes the intended action clear, so usage is implied rather than absent.

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