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

Beyond the annotations (readOnlyHint=false, openWorldHint=true), the description discloses the write-only nature: 'Only ever writes: it cannot read, list or search anything already in their Drive.' It also surfaces the account-connection prerequisite. It does not describe failure behavior when the account is missing, but the key behavioral boundaries are exposed.

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?

Four sentences, front-loaded with the core action and followed by trigger, prerequisite, and constraint. Every sentence adds distinct information; there's no filler or redundant restating of the title.

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?

Given the simple three-parameter schema and the description's coverage of purpose, trigger, prerequisite, and write-only limitation, an agent has everything needed to decide when to call and what the tool does. No output schema exists, but the return value for a save operation is self-evident.

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 input schema already covers all three parameters with descriptions at 100% coverage, so the description need not repeat them. The main description only implies the folder behavior ('We create this folder...' appears in schema, not the description). Baseline 3 is appropriate since schema carries the semantic load.

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 the verb-resource pair 'Save to Google Drive' and specifies the exact scope: a finished file into the signed-in user's own Drive. The closing sentence ('Only ever writes: it cannot read, list or search anything already in their Drive') sharply distinguishes it from any file-read/search sibling. This leaves no ambiguity about what the tool does.

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 states explicit trigger conditions: 'Use as the last step of a workflow when the user asks for the result to be put in, saved to, or uploaded to their Drive.' It also gives an exclusion ('cannot read, list or search anything already in their Drive') and a prerequisite (Google account connected on Integrations page). It doesn't name alternative tools like email_file, but the scope is clear enough to route an agent.

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