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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so safety is fully covered. The description's only added value is scoping the response to metadata rather than file contents, which is genuinely useful, but it says nothing about error behavior on a missing/inaccessible fileId.

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?

A single front-loaded sentence with no filler. Scope and identifier are established immediately.

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?

For a single-parameter read tool with rich annotations and no output schema, the description is nearly sufficient. The residual gap is not clarifying how this differs from read_file or what metadata fields come back, but the core invocation path is unambiguous.

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 required parameter with 0% schema description coverage; the schema only supplies format=uuid. The description adds the meaning ('by fileId' identifies a document or folder), but gives no format, source, or acquisition guidance (e.g., from list_files).

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 plus scope ('metadata for an existing Files document or folder'), which implicitly separates it from read_file (content). However it never names read_file, list_files, or get_file_sharing as alternatives, so an agent must infer the boundary itself.

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?

No explicit when-to-use statement and no named alternatives, despite several near-siblings (read_file, list_files, get_file_sharing, update_file) in the same namespace. 'Existing' is the only hint that a valid fileId must already exist.

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