sheets_append_values

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

Beyond the annotations, the description discloses the non-destructive nature, the API's end-finding behavior, and the return value (updated_range). This is meaningful operational context that an agent needs to predict side effects.

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, front-loaded with the core action, then differentiates from the sibling, then states the return format. Every sentence serves a purpose with no fluff.

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?

With the annotations, input schema, and output description, the tool is fully understood for correct invocation. The description covers what the operation does, how it differs from overwriting, and what the response will contain.

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 description adds context like 'rows' and 'table/range', but the underlying input schema already contains clear descriptions for spreadsheet_id, range, and values. The description does not need to repeat them, but it also does not add substantial new parameter-level guidance.

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 specific verb and resource: 'Append rows after the last row of existing data in a table/range.' It also explicitly contrasts with sheets_write_range, making the tool's role clear among siblings.

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 directly says when to use this tool versus sheets_write_range: 'this never overwrites existing rows' and the Sheets API 'finds the end of the data and inserts after it.' This gives an agent an explicit decision rule.

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