runtime_info

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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description reinforces this with its opening 'Read-only'. It adds useful behavioral context by listing the specific state areas the tool inspects, including the last control restart receipt, going beyond the annotation hints.

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?

One dense, front-loaded sentence that starts with the most important trait, 'Read-only', followed by a compact colon-separated list of all returned information. Every element carries meaningful information and there is no filler.

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?

With zero parameters, strong read-only annotations, and no output schema, the description carries the full burden of explaining what will be returned. It does so by enumerating every visible area of runtime state, making the tool fully usable by an agent without additional lookup.

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 tool has zero parameters, so the baseline is 4. The description does not need to document parameter semantics, and it does not attempt to add irrelevant parameter guidance.

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 uses a specific read-only framing and enumerates exactly what the tool exposes: build commit, worker PID, tunnel ownership, contract fingerprint, capability count, and restart receipt. This clearly distinguishes it from sibling tools like system_info or process_status by naming unique control-plane fields.

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 diagnostic use of a control-plane handshake and the listed fields give an agent a strong hint about when it is relevant. However, it does not explicitly state when to prefer this over related siblings such as system_info, machine_status, or environment_info, nor does it provide exclusion conditions.

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