list_directory

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

Beyond the readOnlyHint annotation, the description discloses that only Markdown files and 'safe child directories' are listed, which is non-obvious filtering behavior. This adds valuable context about what the tool will and will not return, though it does not define what qualifies as 'safe.'

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 a single, front-loaded sentence that conveys the essential purpose without unnecessary words. It strikes an efficient balance between clarity and brevity.

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 read-only listing tool, the description provides the core purpose but omits details about the return format (e.g., whether paths or names are returned) and what 'safe child directories' means. Given the absence of an output schema, these details would help complete the picture.

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 has no descriptions for 'vault' or 'directory,' and the description does not explain their semantics, such as whether 'directory' is optional, relative to the vault root, or what the default '' means. The phrase 'registered vault directory' hints at the vault parameter but leaves the directory parameter ambiguous.

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 clearly states the verb 'List' and the resource 'Markdown files and safe child directories inside a registered vault directory.' This distinguishes it from sibling tools like list_notes or list_vaults by specifying the directory-level scope and the Markdown filter.

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 implies that the tool only works within a 'registered vault directory,' which provides some usage context. However, it does not explicitly mention alternatives or when to prefer this over similar list tools like list_notes or read_note, leaving room for ambiguity.

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