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

Annotations only declare the safety profile (non-read-only, non-destructive, closed-world), so the description carries the rest. It adds the default placement behavior (top-level Drive) and the folder-scoped-access caveat, which an agent needs before calling. It does not mention permissions/scopes required or quota considerations, so it is not exhaustive.

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?

Two sentences, front-loaded with the core action and return values, with no filler. The em-dash clause in the second sentence is slightly convoluted but still earns its place by encoding the conditional requirement.

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 no output schema, the description usefully states the return values (id and link), covers the required mailbox/title context implicitly, and flags the parentFolderId dependency. A note on where the spreadsheet lands relative to list_google_spreadsheets would make it fully self-contained.

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 75%, so most parameters are already documented, and the description largely restates the schema's own text (parentFolderId's folder-restricted requirement, sheetTitles as tabs). It confirms the meaning but adds no new syntax, format, or ordering nuance beyond what the schema provides.

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 states a specific verb and resource ('Create a new spreadsheet in the user's Drive') plus the optional tab behavior and the returned id/link. It is unambiguous on its own, though it never explicitly contrasts itself with the adjacent create_excel_workbook / create_gdrive_folder siblings, relying on the tool name to disambiguate the Google product.

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 gives a concrete conditional rule: the file lands at the top level unless parentFolderId is supplied, and that parameter becomes required when mailbox access is folder-restricted. That is real when-to-use guidance, but it stops short of naming an alternative tool or an explicit when-not-to-use case.

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