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

Annotations already cover read-only/safe/non-open-world, yet the description adds substantial non-obvious context: it reads the locally synced Drive for Desktop folder, requires no Google API or OAuth, and explains what each output `permissions` key means and how a missing key or `read_only: true` should be interpreted. That is real behavioral disclosure beyond what the annotation set provides.

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 core purpose and entry-point guidance are front-loaded in two clean sentences, but the second half is a dense, UI-path-heavy explanation ('LMCP's icon → My apps → open the app's row → the account's Read · Send · Write') that reads like configuration documentation and occupies more than half the text.

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 an output schema present and no parameters, the description covers purpose, sequencing relative to siblings, auth model, and output field semantics — nearly everything needed to call it. It omits edge cases such as what happens when Drive for Desktop isn't installed or no accounts are synced.

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 tool takes zero parameters, so the baseline is 4 per the rubric; the description correctly adds no parameter detail because none exists. The output-field explanation belongs to output semantics rather than parameters, so it doesn't raise this score further.

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?

States a specific verb and resource — 'Lists the Google Drive folders synced on this Mac' — and enumerates the scope (My Drive, Shared drives, per-account mounts). An agent can immediately distinguish it from gdrive_list_files or gdrive_search_files, which operate on contents rather than roots.

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?

'Start here to get valid paths for the other gdrive_* tools' explicitly routes the agent to this tool before the siblings that need paths. It gives clear positive guidance but no exclusions or when-not conditions (e.g. unlike onedrive_root for OneDrive, which is never mentioned).

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