list_vaults

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

With no annotations provided, the description carries the full burden. It communicates that the tool lists all vaults and returns their IDs and capabilities, implying a read-only operation. However, it does not disclose any potential side effects, authentication requirements, or limitations, though the simple nature of the tool likely makes these minimally relevant.

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 efficiently conveys the tool's purpose and output. Every word earns its place, with no redundancy or extraneous information.

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 no-parameter tool without an output schema, the description adequately covers what the tool does and what it returns. It mentions IDs and capabilities, which is sufficient for basic invocation. The description is complete enough given the tool's straightforward nature.

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 tool has zero parameters, so the schema is trivially 100% covered. No parameter descriptions are needed, and the baseline of 4 applies here because there is nothing for the description to add about parameters.

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 a specific action ('List all configured Obsidian vaults') with a distinct resource and additional output details ('with their IDs and capabilities'). It distinguishes itself from sibling tools like list_files_in_vault or get_vault_stats by focusing on vaults themselves rather than their contents or statistics.

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 context for when to use this tool: to discover all configured vaults. While it doesn't explicitly state when not to use it or name alternatives, the phrasing and resource specificity make the usage context obvious without needing exclusions.

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