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

With no annotations to carry the safety/behavior burden, the description does disclose the main side effect: the call resets the watchdog timer. It doesn't cover authentication requirements, error behavior, or consequences of an expired/missing watchdog, but for a simple keep-alive action the key behavior is present.

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 compact and front-loaded: the core action and the invocation frequency are both stated in two short sentences. The opening 'Still alive.' is somewhat decorative, which prevents a full 5, but it doesn't bloat the definition.

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 two-parameter tool with no output schema and no nested objects, the description covers the main purpose and operational frequency. It falls short by not explicitly explaining the 'name' parameter or the relationship to watchdog setup, though these can be loosely inferred from the resource word 'watchdog.'

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?

The required 'name' parameter has no schema description, and the tool description only indirectly implies it is the watchdog identifier. The optional 'vigil_key' parameter is already well documented in the schema, so the description adds only marginal parameter meaning rather than fully compensating for the gap.

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 identifies a specific action—'Reset a watchdog's timer'—on a concrete resource, which is enough to distinguish it from sibling tools like vigil_set_watchdog, vigil_watchdog_status, or vigil_delete_watchdog. The 'Still alive.' framing reinforces the liveness/heartbeat semantics without obscuring the operation.

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 phrase 'Call this at least once per interval' gives an explicit timing requirement for using the tool. However, it doesn't mention alternative tools or when not to use it, and it doesn't state a prerequisite such as the watchdog needing to exist or be set up first.

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