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

Annotations supply the safety profile (readOnlyHint=false, destructiveHint=false), so the description only needs to add operational context. It does say the call keeps the kernel alive and updates capabilities, but omits frequency expectations, idempotency, and any auth/registration prerequisite tying it to operator status.

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 tight sentences that front-load the core action. A little more specificity would fit without bloat, but nothing is wasted.

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?

A mutating heartbeat with no output schema, 0% parameter documentation, and no stated return behavior leaves the agent guessing about what a successful response means and what shape capabilities must take. The description should do more given the missing schema coverage.

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 0% across two parameters, so the schema documents nothing. The description hints that the 'capability re-announcement' maps to the capabilities array and that kernel liveness maps to kernelId, but gives no expected structure for the capability objects or format constraints.

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 clear verb+resource ("Operator sends heartbeat") and adds the effect of keeping the kernel alive and refreshing capabilities. It does not explicitly distinguish itself from the sibling kernel_heartbeat or kernel_announce_capabilities, so an agent must infer the operator-side role rather than read it.

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 never says when to call this versus kernel_heartbeat, kernel_announce_capabilities, or get_operator_status. No timing, frequency, or context guidance is given; the agent must infer that this is a periodic liveness call.

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