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

Annotations only supply readOnlyHint=true; the description adds substantial behavior beyond that: truncation with a `truncated: true` marker, Google-native export defaults (text/plain, text/csv for spreadsheets), direct UTF-8 reading with garbling for binaries, and the required Drive CONTENT scope plus reconnect fallback. This is exactly the context annotations cannot carry.

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-loads the core action, then layers routing guidance, truncation behavior, auth requirements, and the account condition in compact prose. Every sentence carries distinct information; nothing is 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 covers the return shape (text content, truncation flag) and the failure/authorization paths (reconnect hint, binary garbling). An agent has everything needed to invoke it correctly without guessing.

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 all three parameters (account, file_id, export_mime_type) are already documented in the schema, including the export defaults. The description restates the account and export behaviors rather than adding new syntax or constraints, so the baseline 3 is appropriate.

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 one Drive file's TEXT content by id.' The emphasis on TEXT and the by-id framing immediately distinguish it from download_file_content (binary) and the Slack/Notion readers in the sibling list.

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?

Explicitly routes binary formats to download_file_content ('garbles binary formats like images/PDFs — use download_file_content for those'), states when the account parameter is needed, and notes the reconnect hint for accounts lacking the drive.readonly CONTENT scope. When/when-not/alternative are all present.

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