Send a command to a protected device through the NetGuard broker

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

With no annotations, the description carries the full burden and does substantial work: it names the three verdicts and their consequences, states that unenrolled sources are denied, that out-of-limit parameters are denied outright, and that every decision is audit-chained. The remaining ambiguity is whether this tool only evaluates or also performs the forward, since the title says 'send a command' while the description says evaluate before forwarding.

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?

Four short sentences, front-loaded with the core action and followed by the verdict semantics, with zero filler. Each sentence contributes either the purpose or a behavioral rule the agent could not otherwise know.

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?

There is no output schema and no annotations, so the description must cover returns and safety behavior; it covers the verdicts and denial rules but not what accompanies a verdict (reason, policy reference, audit identifier) or the enrollment/auth requirements in any detail. For a six-parameter policy-gate tool, that leaves meaningful gaps for an agent deciding how to call it and how to interpret the result.

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 only 33% (just source and description are documented), so the description needed to compensate for the undocumented parameters. It adds only an indirect hint that 'parameters outside hard safety limits are denied,' without explaining kind's enum values, deviceId, setpointC units, or defrostMinutes. An agent still cannot tell from this text what setpointC range is safe or how the custom kind behaves.

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: 'Evaluate a command for a NetGuard-registered device BEFORE it is forwarded.' It usefully corrects the impression created by the tool name and title ('Send a command'), making clear this is a gatekeeper evaluation rather than an execution. However, it never distinguishes itself from the sibling sentinel_evaluate_action, which by name appears to do something very similar.

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 'BEFORE it is forwarded' implies the point in the workflow where this tool belongs, and the verdict list clarifies the decision outcomes. There is no explicit when-not guidance and no routing to alternatives such as sentinel_evaluate_action or sentinel_explain_policy, so an agent facing those siblings has to infer the boundary itself.

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