Record a safe stop

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

Beyond the annotations, it discloses append-only behavior ('adds a new stop and never replaces an earlier one'), that it 'neither moves the focus nor closes anything,' how the result interacts with vivac_brief, and even what the return payload contains (uncommitted files, unpushed commits, unclaimed changes). This is rich behavioral context the annotations alone do not convey.

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?

Purpose and the append-only guarantee are front-loaded, and each sentence contributes meaning. It is on the longer side, but no sentence is pure filler, so it stays efficient.

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 compensates by describing the result ('says what the stop found unfinished: files not committed, commits not pushed, and files changed that no node claims'). Combined with usage triggers and behavioral rules, an agent has everything needed to call it correctly.

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 coverage is 100%, so both parameters are already documented. The description's framing ('what was about to happen next') restates the schema rather than adding syntax or edge-case detail, so the baseline 3 applies.

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 gives a specific verb and resource ('Record a safe stop') and immediately defines what a stop is: 'a label for this point and what was about to happen next.' It explicitly distinguishes itself from siblings by naming vivac_park and vivac_note and their different purposes.

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 states exactly when to call it ('at a clean seam: before the session ends, before a long pause or a handoff, or when the person asks for a safe point') and routes the agent to alternatives for adjacent needs ('To set a node aside, vivac_park; to keep a fact on one, vivac_note'). Nothing is left to inference.

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