set_vault_root

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

With no annotations, the description carries the full burden and does so: it states the side effects (records the path, creates and seeds the directory), that changes take effect immediately with no restart, that the failed call can be retried, that a `notice` may be returned when files are moved, and the exact failure condition for managed installs.

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 critical facts (what it does, when to call, immediate effect) are front-loaded, and the Args section is precise. The middle paragraph on asking the user for a path is longer than strictly necessary, though it is genuinely operational guidance rather than filler.

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?

There is no output schema, but the description enumerates the return fields ({vault_root, created, configured_at} plus optional `notice`) and instructs the agent to relay the notice verbatim. For a two-parameter configuration tool, nothing an agent needs to call it correctly 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 0%, so the description must compensate, and it does: `path` is documented as an absolute path with `~` expansion, and `create` is explained with its False semantics (adopt an existing vault only; any other path fails without writing anything). This adds meaning well beyond the bare schema types.

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 opens with a specific verb and resource: 'Point Loci at the user's vault directory.' It also names the return shape and distinguishes this configuration tool from the many vault read/write siblings by framing it as the setup step that makes them work.

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?

It gives explicit triggers ('when a tool has failed with LOCI_NOT_CONFIGURED', 'when the user asks to move Loci to a different vault') and an explicit exclusion ('Fails when the deployment sets LOCI_VAULT_ROOT... cannot be changed from chat'). It also prescribes the interaction protocol: ask for the path first, never guess, never offer a default.

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