Download file content

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

Even with readOnly/idempotent annotations, the description adds meaningful behavioral detail: overwrite refusal unless overwrite=true, inline size/type limits, rejection of Google-native files, shortcut resolution, and abuse-download restrictions. No contradictions with annotations.

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 description is front-loaded with the core action, then uses compact conditional clauses to cover modes, exceptions, and edge cases. Every sentence carries essential routing or behavioral information without filler.

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 still tells the agent what to expect in each mode (saved_to/bytes vs inline content) and all relevant caveats. An agent has enough information to decide when and how to invoke the tool, including what to do for Google-native and flagged files.

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 100%, so the baseline is 3, but the description adds real value beyond the schema: it explains the overwrite refusal behavior and the owner-only constraint on acknowledge_abuse. It could have also clarified file_id, but the schema already documents that adequately.

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 ('Downloads a binary file's bytes') and immediately clarifies the two operating modes. It also explicitly separates itself from export_file for Google-native files, making sibling differentiation clear.

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 concrete decision rules: use save_path for writing to disk, inline return for small text files, export_file for Google-native files, and acknowledge_abuse for flagged files. It explicitly names an alternative tool and the condition that selects it.

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