tool_coexistence_status

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

With no annotations provided, the description carries the full burden and does disclose the key behavioral trait: 'Read-only.' It also sets expectations about the returned data by listing tunables, health, and timing information. It does not cover access prerequisites or failure behavior, but those are less critical for a stateless status report.

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?

A single dense sentence with the core purpose front-loaded before a colon-delimited list of report contents. Every phrase earns its place, and the description avoids padding while remaining technically precise.

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 zero-parameter, read-only status tool with an output schema, the description provides both when to invoke it and what data to expect. The output schema covers the return structure, so nothing an agent needs to call this tool correctly is missing.

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 there is no schema description to compensate for; the 0-param baseline is 4. The description still adds semantic context by enumerating what the caller receives, which is useful even though there are no inputs to document.

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 specific verb ('Report') and resource ('coexistence policy in force'), then enumerates exact contents such as the admission gate, tunables, named-mutex health, and last physical input. This clearly distinguishes it from sibling action tools like tool_click_at and tool_send_keys, which perform UI operations rather than report policy state.

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?

Explicitly states when to call it: 'call it when an action was refused with user-active or arbiter-busy and you want the numbers behind the refusal.' It also frames the tool as read-only, making it clear this is a diagnostic fallback rather than a routine action; no alternative tool is needed because no sibling offers this state.

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