Extends a running motion lease via heartbeat, capped at 5 seconds per renewal and 20 seconds total, keeping owner-approved robot actions valid.
Extend the running motion lease (heartbeat). At most 5 s from now and 20 s in total.
| Name | Required | Description | Default |
|---|---|---|---|
| extend_s | Yes | ||
| lease_id | Yes |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations only supply readOnlyHint=false. The description adds a genuinely non-obvious behavioral limit: the 20 s total lease lifetime cap, which is not encoded anywhere in the schema. It still omits failure behavior (e.g., what happens when the total cap is exceeded) and what the operation returns.
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 short sentences with the core action front-loaded and constraints appended. No filler, no restatement of the tool name.
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 state-mutating, no-output-schema tool, the description covers the action and its hard limits but not the lease lifecycle context an agent needs — what an expired or unknown lease_id yields, whether the renewal is idempotent, or how it relates to reins_status/reins_stop.
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 0%, so the description must carry the load. 'At most 5 s from now' partially explains extend_s (seconds, capped), but lease_id is left unexplained beyond its self-descriptive name, and the per-call vs. total limits are easy to conflate.
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 and resource: 'Extend the running motion lease (heartbeat).' The parenthetical disambiguates the domain meaning of 'renew.' It does not explicitly contrast with siblings like reins_stop or reins_status, but the purpose is unambiguous.
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 'heartbeat' framing implies periodic calling to keep a lease alive, and the caps hint at how often it may be used, but there is no explicit statement of when to call it, when not to, or what happens if the lease has already lapsed. Usage is only implied.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.