Pillars, rules and invariants

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

Annotations already establish read-only, non-destructive, closed-world behavior. The description adds genuinely non-obvious operational context: commands are folder-relative to the folder holding .vivac, running them elsewhere 'can pass without checking anything,' and the tool only supplies rules while 'the judging is yours.' It stops short of describing volume or pagination.

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?

Front-loaded with the payload ('What governs this project: ...') and free of filler sentences. Some clauses are densely nested ('each with the folder it runs in, relative to the folder that holds .vivac, or none, which means it is judged'), which costs a little readability but the length is justified for a no-parameter tool whose return shape has no output schema.

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?

With no output schema, the description carries the full burden and does: it describes the return shape, the field meanings, the empty-result case, the consumption caveat, and the follow-up action. Nothing an agent needs in order to call and use this correctly appears to be 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?

Zero parameters, so per the rubric the baseline is 4 and there is nothing for the description to add or omit. The schema is trivially complete.

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?

States a specific resource and enumerates its contents: pillars, rules under them, rules without a pillar, and invariants. It also describes the internal structure of each element (title says what a pillar rejects, rules carry verifying commands). It does not name or contrast any sibling tool (e.g. vivac_brief, vivac_declare), so differentiation is left to the caller.

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?

Gives an explicit trigger: 'Read it whenever you are asked to check work against the project's rules, whether or not they arrived when the session opened.' It also covers the alternative path for the empty case, routing the agent to vivac_add with a concrete procedure (propose pillars/rules, let the person decide, write them).

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