Apps Script MCP

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. It states this is an update operation but doesn't mention whether it overwrites existing values, requires specific permissions, has rate limits, or what happens on errors. The description lacks crucial behavioral context for a mutation tool.

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 efficiently structured with a clear opening statement followed by a well-organized parameter list. Every sentence adds value, and there's no redundant or unnecessary information.

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 that this is a mutation tool with no annotations, 5 parameters, and an output schema exists, the description does an adequate job explaining parameters but lacks critical behavioral context like permissions, error handling, and sibling tool differentiation. The presence of an output schema helps, but the description should do more for a tool that modifies data.

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. It provides clear explanations for all 5 parameters, including examples for 'range' and 'values', and clarifies the 'value_input' enum options. This adds significant value beyond the bare schema, though it doesn't fully explain data format constraints for 'values'.

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 states the verb 'Update' and resource 'values in a Google Sheet', making the purpose specific and understandable. However, it doesn't explicitly differentiate from sibling tools like 'append_sheet_values_tool' or 'modify_doc_text_tool', which prevents a perfect score.

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 no guidance on when to use this tool versus alternatives like 'append_sheet_values_tool' or 'get_sheet_values_tool'. There's no mention of prerequisites, such as authentication or permissions, which are critical for Google Sheets operations.

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