sheets_append_values

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

The description discloses the critical default behavior that existing empty cells will be overwritten, which adds meaningful context beyond the destructiveHint=false annotation. It also offers a clear remediation path (INSERT_ROWS). It does not mention authentication, return values, or effects on non-empty cells, but the key risk is addressed.

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 two sentences with no wasted words. The important warning about overwriting is front-loaded and immediately actionable, and the structure makes it easy to scan.

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 5 parameters, nested values array, and lack of output schema, the description covers the most consequential behavioral nuance (insert vs overwrite) while the schema handles parameter details. It could mention return values or explicitly compare with sheets_update_values, but it is largely sufficient for the task.

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?

The input schema already documents all 5 parameters with 100% coverage, so the baseline is 3. The description adds value by explaining the practical implication of the insertDataOption enum (OVERWRITE vs INSERT_ROWS) and its default, which the schema alone does not convey. It does not add detail for values or range, but those are already well-described in the 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 clearly identifies the specific action ('Append values to the end of a table') and the resource ('Google Sheets spreadsheet'), which distinguishes it from update, clear, and insert-related sibling tools. The mention of 'end of a table' makes the scope precise and differentiates it from other write operations.

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 provides clear context that this tool is for appending to a table and explicitly tells the user how to choose between overwriting empty cells and inserting new rows via insertDataOption. However, it does not explicitly name alternative sibling tools or give a when-not-to-use statement, so it falls short of full exclusion guidance.

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