list_vaults

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

The description correctly implies a read-only, non-destructive operation (listing vaults). Without annotations, it carries the full burden, and it adequately describes the function. However, it does not detail the output format or any side effects, leaving some behavioral ambiguity.

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 concise sentences deliver the core purpose, the key use case, and a critical scope note. No unnecessary words; the most important information is front-loaded.

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 zero parameters, the presence of an output schema, and the clear description, all necessary information is provided. The description covers the tool's action, utility, and scope, making it fully actionable for the agent.

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 input schema has zero parameters, so the description's role in parameter semantics is minimal. It adds value by explaining the output (paths) and the use case (vault name discovery), which goes 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?

Clearly states the action 'list all vaults known to this machine, with their paths' and explicitly distinguishes the machine-level scope from vault-specific operations. The utility for discovering the vault name is directly stated, leaving no ambiguity about the tool's purpose.

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 clear guidance that the tool is for discovering vault names to set the OBSIDIAN_VAULT environment variable. It explicitly notes the machine-level scope, contrasting with vault-scoped tools. However, it does not explicitly describe when to avoid this tool or name specific alternatives, which would improve the score.

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