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

Annotations already indicate non-read-only and non-destructive behavior. The description adds valuable behavioral context: it returns the spreadsheet ID and URL, it optionally fills rows (implying empty sheets are possible), and it requires a Google Drive connection. These details go beyond the annotation hints and help the agent understand side effects and prerequisites. No contradiction with annotations.

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 and well-organized: it leads with the core purpose, explains the data format, states the return value, and ends with the connection prerequisite. Every sentence adds functional value, and the length is appropriate for the tool's simplicity.

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 tool with 2 optional parameters and no output schema, the description covers all necessary aspects: what it does, how rows are structured, what it returns, and the required connection. The agent has enough information to invoke it correctly without ambiguity. Missing details like default title behavior are minor and not critical for correct invocation.

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?

Since schema description coverage is 100% and both parameters ('rows' and 'title') already have descriptive text in the schema, the description adds little new meaning. It repeats the row-array structure and headers note, but does not introduce novel syntax, formatting rules, or default behavior. Baseline 3 is appropriate when the schema handles parameter documentation.

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 action ('Create a new Google Spreadsheet'), the location ('in the user's Drive'), and the optional data filling capability. It distinguishes itself from sibling sheet tools (append, update, read) by focusing on creation, and it provides concrete examples (swipefile, ad list, performance report) that make the purpose immediately understandable.

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 clear context on when to use this tool (creating a new spreadsheet, optionally populating it) and even gives example use cases. It does not explicitly name alternatives or state when-not-to-use, but the distinction between creating vs appending/updating is implicit and clear. The connection requirement is also stated, which is a useful precondition.

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