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

With no annotations, the description carries the burden and discloses key behaviors: the 50-item limit, descending sort by updatedAt, flat list ignoring folder hierarchy, folder omission, and gating behind FILES_SURFACE_ENABLED + per-user allowlist. This is substantial, though it doesn't detail response content or edge cases like empty results.

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 four concise sentences, front-loaded with the core action and key parameters, followed by use-case, exclusions, and access-control context. Every sentence adds value with no redundancy or fluff.

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 two parameters with full schema coverage, no output schema, and no annotations, the description effectively covers the tool's purpose, behavior, limits, and gating. It lacks explicit return-value details, but for a simple listing tool this is not a major gap. The context is sufficient for an agent to select and invoke the tool correctly.

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 provides 100% coverage for both parameters, including accepted forms for the slug. The description does not add additional parameter-level detail or examples, so it neither enhances nor detracts from the schema. 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?

The description states a specific verb and resource: 'List the 50 most recently updated files in a Files surface, sorted by updatedAt descending.' It clearly distinguishes from siblings by noting the flat surface-wide scope, ignoring folder structure, and omitting folders, which separates it from list_files and similar tools.

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 provides clear when-to-use context: 'Useful for an agent answering what changed lately or show me yesterday's uploads without paging through the folder tree.' It implies when not to use it via 'Flat surface-wide list; ignores folder structure,' but does not explicitly name an alternative tool, so it falls slightly short of a 5.

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