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

Goes well beyond the readOnlyHint annotation by disclosing quota behavior (MCP does not report remaining quota), the daily-cap error path, the exact supported MIME types, the 500 MiB size ceiling, and the mapping of failure conditions to error_codes and next_action values. This is unusually rich for a status 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?

Front-loaded purpose, then tightly packed operational facts. Dense but every sentence carries information an agent needs; the enumeration of MIME types and error codes is verbose but justified by their absence from any output schema.

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 carries the return-shape burden and does so well by naming the fields an agent must react to (next_action, bind_url, error_code). It does not describe the success-path payload structure, which is the remaining gap.

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?

One parameter (connection_context) with 0% schema description coverage, and the description never explains it. It is likely a system-injected context token, so the gap is tolerable, but the description does nothing to compensate.

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?

Opens with a specific verb+resource+scope: 'Read-only Google Drive cloud-library status for the current user.' It explicitly disambiguates from a near sibling ('This is not the upload library'), which is exactly the differentiation an agent needs.

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?

Gives concrete operational guidance: when next_action is bind_in_browser/rebind_in_browser, surface bind_url, and clarifies that binding is done by a person in the dashboard rather than settings. It does not, however, state when to prefer this over creatives_list_cloud.

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