Extend a task lease

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

With no annotations, the description carries full burden. It explains the effect (extends lease by extraMs, prevents reaping) and the critical requirement of carrying the fencingToken. It does not mention failure modes, but this is acceptable for a simple heartbeat operation.

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, no wasted words. Front-loaded with the verb 'Heartbeat', immediately conveying the tool's purpose. Every part earns its place.

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?

For a simple lease-extension tool with no output schema and no annotations, the description is sufficiently complete. It explains the action, the reason, and the necessary parameter semantics. Could add error conditions, but not essential.

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 only 33% (extraMs only). The description adds meaning to fencingToken ('must carry the claim') and re-emphasizes the role of extraMs. taskId is implicit by context but not detailed; however, it is self-explanatory.

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 uses a specific verb ('extend') and resource ('task lease'), clearly distinguishing it from sibling tools like claim_task, ack_task, and nack_task. The phrase 'Heartbeat a long-running task' adds concrete operational context.

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 when to use: for long-running tasks needing lease extension to avoid being reaped. It does not explicitly list alternatives, but the context strongly implies this is for already-claimed tasks, distinct from claiming or acknowledging.

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