renew_lease

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

With no annotations provided, the description carries the full burden. It discloses a key behavioral trait: the operation fails if the lease was reaped or reassigned, which is valuable. However, it does not disclose whether the extension is idempotent, whether it resets the lease timer from the current time, or what happens to the old lease generation. The failure condition is useful but incomplete for a mutation tool with zero annotation coverage.

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 two sentences with no wasted words. The core action is front-loaded, and the failure condition is a useful addition. It is appropriately sized for the tool's complexity.

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 tool has 4 parameters, 2 required, no output schema, and no annotations. The description explains the basic operation and one failure mode, but it does not cover the concurrency semantics of lease_generation, the clamping behavior of lease_seconds (though the schema covers that), or what the response contains. For a lease-extension tool, the missing concurrency context is a notable gap, but the description is not severely incomplete.

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 50%, so the schema documents binding_token and lease_seconds but not task_id or lease_generation. The description adds meaning by explaining that the lease is on a TASK and that lease_generation relates to reaping/reassignment, but it does not explicitly explain that lease_generation is the current generation required for optimistic concurrency, nor does it clarify the role of task_id beyond identifying the task. It partially compensates for the schema gap but leaves the two undocumented required parameters under-explained.

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 states a specific verb ('Extend') and resource ('the caller's lease on a TASK'), which clearly identifies the operation. It does not explicitly differentiate from sibling tools like renew_resource or worker_heartbeat, but the resource and mechanism are distinct enough that the core purpose is clear.

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 description implies usage context: it is for extending a lease the caller already owns, and it names failure conditions ('Fails if the lease was reaped or reassigned'). However, it does not explicitly state when to prefer this over alternatives like renew_resource or worker_heartbeat, nor does it mention prerequisites like joining a session or claiming the task.

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