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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, covering the safety profile. The description adds mild behavioral context by saying it returns note counts across all folders, but it does not disclose ordering, recursion, or any selection criteria beyond all folders. This is comparable to the calibration case where minimal extra context earns a 3.

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?

Two short sentences with no filler. The key behavior is front-loaded, and the usage guidance follows immediately. Every word contributes.

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 simple list tool, the description, annotations, complete parameter schema, and output schema together supply everything an agent needs: what it returns, why to use it, safety guarantees, and parameter handling. Nothing critical 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?

Schema description coverage is 100%, and the vault_id parameter is already thoroughly documented in the input schema, including when to pass it and how name resolution works. The description adds no parameter-level meaning, so the baseline of 3 applies.

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 (list), resource (all folders), and scope (personal knowledge base), and adds that results include note counts. This clearly distinguishes it from the sibling list_folder tool by explicitly saying 'all folders' and by focusing on organizational structure.

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 sentence 'Use to understand the vault's organization' provides a clear, purpose-driven context for when to call this tool. However, it does not explicitly contrast with alternatives such as list_folder or list_vaults, so it stops short of offering when-not-to-use guidance.

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