Send a POSIX signal to a process by PID to stop, terminate, or control its execution. Specify signal names like SIGTERM or SIGKILL.
Send a POSIX signal to terminate or signal a process by PID.
| Name | Required | Description | Default |
|---|---|---|---|
| pid | Yes | Process ID to signal. | |
| signal | No | Signal name (e.g. SIGTERM, SIGKILL, SIGHUP, SIGINT). | SIGTERM |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden. It discloses the core behavior (signaling can terminate a process) but lacks details on permissions, error handling, or signal-specific consequences (e.g., SIGKILL cannot be caught). This is minimal but not misleading.
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 sentence that front-loads the action and target with zero wasted words. Every word earns its place.
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 a fully documented schema and no output schema, the one-sentence description is nearly sufficient. It could mention the default signal or force-kill caveat, but the schema already declares SIGTERM as default, so the gap is minor.
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 description coverage is 100%, so params (pid, signal) are already fully documented with types, defaults, and examples. The description adds no additional parameter semantics, which is acceptable per baseline.
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?
Description uses a specific verb ('send') and resource ('POSIX signal') targeting a process by PID. It clearly distinguishes this tool from siblings like process_list, process_set_priority, and run_command by stating exactly what it does.
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 usage: when a process needs to be signaled or terminated by PID. However, it provides no explicit alternatives, prerequisites, or when-not-to-use guidance compared to related process tools.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.