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

With no annotations at all, the description carries the full burden of behavioral disclosure, and it delivers thoroughly. It reveals ordering behavior ('most recently changed first'), output scope ('names and ids only'), query semantics ('narrow by name'), and an important access-related limitation ('spreadsheets outside the folders you have access to are not returned'). The note about the list being shorter than the page size under folder rules is a valuable edge-case disclosure that an agent would not discover from the schema alone.

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?

Three sentences with no filler. The main purpose is front-loaded, followed by the output limitation, query usage, and a caveat about access restrictions. Every sentence earns its place and adds distinct information. This is an exemplar of concise but informative tool documentation.

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 read-only list tool with two parameters and no output schema, this description covers everything an agent needs: what the tool returns (names and ids), the ordering, the optional query's purpose, and the access-filtering caveat. The mailbox requirement is already fully described in the schema, and no output schema exists to require return-value documentation. There are no missing pieces that would impede 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?

Schema-described coverage is 50%: the mailbox parameter is well-documented in the schema, but the query parameter has no schema description. The tool description compensates by explaining that query is used to 'narrow by name,' giving the agent meaningful semantic context for the otherwise bare string parameter. It could go further with syntax details (e.g., exact match vs. contains), but it adds sufficient value above 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 opens with a specific verb and resource: 'Find spreadsheets in the user's Drive,' making the tool's purpose immediately clear. It further differentiates from siblings by stating it 'returns names and ids only — no cell data,' which disambiguates it from tools like read_google_sheet_range or get_google_spreadsheet. The scope is well-defined and distinct from list_gdrive_items and list_excel_workbooks.

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 gives clear context for when this tool is appropriate: finding spreadsheets by name and returning a lightweight list. The statement 'no cell data' implies a boundary — this tool is not for reading spreadsheet contents — though it does not explicitly name alternative tools like read_google_sheet_range. It also provides guidance on using the query parameter to narrow results, which is practical usage direction. It stops short of explicit when-not-to-use with named alternatives, so a 4 is appropriate.

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