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

With no annotations, the description carries the burden of behavioral disclosure. It adds useful context: status:'fail' reports a failure immediately and the capsule is stored on the key tier for dead-man resume state. However, it does not mention side effects, expected response, or behavior when the monitor is not registered.

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 sentences, with the purpose front-loaded in the first phrase. The second sentence efficiently packs capsule guidance, storage location, and failure semantics without 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?

The description covers purpose, capsule usage, and failure mode, which is a solid basis for a simple ping tool. However, with no output schema and no annotations, it omits the response format and error handling, so an agent may be unsure what to expect after invoking it.

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 description adds meaningful semantics beyond the schema: it defines the capsule shape (`{ step, done: [...], next, ids: {...} }`), the 32KB size limit, and clarifies that status:'fail' triggers immediate failure reporting. The monitor_id and secret are left to the schema, but the most nuanced parameters are enhanced.

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 identifies the tool as a 'still alive' ping for a registered monitor, specifying the resource and the immediate-failure behavior of status:'fail'. This distinguishes it from the sibling tools like register_monitor and fetch_capsule by its core function.

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 the tool is for a registered monitor, implying a prerequisite of register_monitor and framing the use case as periodic liveness pings. It does not explicitly list alternatives or when-not-to-use scenarios, but the context is clear enough.

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