worker_heartbeat

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

With no annotations, the description carries the full burden and does disclose the core behavior: it mutates heartbeat_at and thereby affects reaper treatment. But it does not cover edge cases like missing worker node, invalid binding_token, idempotency, or return behavior.

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?

One tight sentence front-loads the action and immediately ties it to the reaper's staleness behavior. There is no filler or repeated schema information.

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 definition is adequate for a simple heartbeat tool, but the absence of annotations and output schema leaves the agent without explicit information about return values, failure modes, or how frequently the heartbeat should be sent relative to the reaper threshold.

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 the baseline is 3. The description adds no parameter-specific guidance, but the schema already explains the worker_id default and binding_token's role in identity, so there is no gap to compensate for.

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 verb and resource: 'Stamp heartbeat_at on the calling agent's WORKER node'. It also gives the observable consequence (avoiding reaper staleness), which clearly distinguishes this liveness tool from lifecycle siblings like renew_lease or complete_worker.

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?

The intended use is implied well by the reaper/stale framing: call it to keep the worker from being reaped. However, it never explicitly says when or how often to call it, nor does it contrast with alternatives such as renew_lease for lease-specific renewal.

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