ghost_key

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

Despite no annotations, the description discloses the default background posting behavior, the supported key classes including semantic messages for editing shortcuts, the error for unsupported modifier combos, and the fallback when no anchor/window is set. This covers the agent's key decision points for side effects and limitations.

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?

Five dense sentences with zero fluff; the headline behavior is front-loaded, then supported details, then alternatives. Every sentence adds information.

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 key-sending tool with policy modes and anchoring rules, the description covers default behavior, limitations, alternatives, and fallback. It doesn't describe return values or error format, but the output schema is absent and the behavior around errors is at least mentioned ('error naming the alternative').

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?

Input schema already covers all three parameters (100%), so baseline is 3. Description adds meaningful nuance: 'window' anchors by title substring and omitting it falls back to session anchor or human foreground window; 'background' is a compatibility flag since posting is already default. This goes beyond the schema.

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 action ('Send a key to a window') and a critical differentiator ('WITHOUT focusing it'), and clarifies target resolution via 'window=' or session anchor. Names a sibling (ghost_act) as alternative, so it stands apart.

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 recommends ghost_act action=type for text, warns that other modifier combos have no background path and will error naming the alternative, and states hold/release exist only under foreground policy. This gives the agent clear conditions for selecting this tool over alternatives.

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