list_folders

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

Even though no annotations are provided, the description fully discloses behavioral traits: 'Read-only; no side effects, auth, or rate limits' and 'Throws if project_id references an unknown project'. This covers safety, error handling, and permissions comprehensively.

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?

Five concise sentences, each serving a distinct purpose: core action, return shape, safety, error behavior, and usage guidance. No redundancy or filler; every sentence earns its place.

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?

The description is fully self-contained for a 1-parameter tool with no output schema or annotations. It explains return format, relative path semantics, error behavior, and relationships to sibling tools, making external context unnecessary.

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 already documents project_id with 100% coverage ('Pass null or omit to list KB folders'). The description adds the error condition for unknown projects and clarifies the Knowledge Base context, providing extra value beyond the schema.

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?

Description clearly states the action: 'List folder paths under a project root (or the Knowledge Base when project_id is null/omitted)'. It also distinguishes from create_folder by explicitly noting that to create a folder one should use create_folder.

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?

Provides explicit use cases: discovering where to drop a new file via create_file's folder argument or navigating vault structure. It also names create_folder as the alternative for creation, guiding the agent on tool selection.

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