files.list

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

With no annotations provided, the description carries the full burden and does so admirably. It declares read-only semantics, the absence of side effects/auth/rate limits, the per-row annotation fields, and the presence of `total_est_tokens` in the response. It also explains the `project_id: null` behavior which is a non-obvious trait.

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?

Every sentence carries distinct, non-redundant value: purpose, safety, response shape, special-case semantics, and sibling routing. The critical scoping constraints (`project_id: null` vs omit) appear early, and the whole description is dense but not verbose.

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 no output schema, the description adequately explains the return format (per-row annotations plus `total_est_tokens`). All 8 parameters are semantically covered across schema and description, safety traits are disclosed, and guidance for selecting among relevant siblings is included. Nothing an agent needs to call this tool correctly is missing.

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 schema already covers 100% of the parameters, so the baseline is 3. The description adds meaningful semantics beyond the schema: it clarifies that `project_id: null` returns ONLY Knowledge Base files while omitting the field spans everything, and that `kind` narrows to one content class. This elevates it above the baseline, though the remaining parameters are straightforward.

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+resource ('List file metadata') and enumerates the exact filtering dimensions. It explicitly contrasts itself with sibling tools (`files.search`, `projects.map`) by naming them and their distinct use cases, making it unambiguous which tool an agent should pick.

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 explicit when-to-use guidance ('Use to browse known structure') and names the two key alternatives with their conditions (`files.search` for keyword/content lookup, `projects.map` for a denser whole-vault dump). It also clarifies the subtle `project_id: null` vs omit distinction, which is crucial for correct invocation.

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