Heartbeat Decision Task

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

The description goes beyond the sparse annotations by disclosing the 409 behavior for stale/foreign epochs, the prescribed reaction (stop, discard, re-list), and the auth failure modes with named error codes. It also specifies the lease extension limit relative to sla_deadline_at, which is useful runtime 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?

The description is organized into labeled sections (USE WHEN, NOT FOR, ARGS, AUTH) that are easy to scan and each earns its place. It is dense but free of redundancy, with the most important purpose statement first.

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 two-parameter tool with no output schema and meaningful auth/error nuance, the description covers when to use it, what it does, how parameters relate to the claim, what errors mean, and how to handle auth failures. Nothing essential for correct invocation is 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?

Schema coverage is 100%, so the schema already documents both parameters well. The description adds practical meaning by saying 'using the epoch from claim' and clarifying that a foreign epoch also returns 409, plus the recovery action. This is a meaningful but not large increment over the schema.

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 opens with a specific verb and object ('Extend the lease on a claimed decision task') and adds a hard constraint ('never past its sla_deadline_at'). It also explicitly names sibling tools it is not for, so an agent can distinguish it from claim, submit, release, and fail at a glance.

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 USE WHEN line gives the exact condition for invoking the tool, and the NOT FOR line lists the specific alternative tools for different lifecycle stages. This is explicit routing guidance with no inference required.

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