Fetch recent Linux system logs from journalctl, filtering by unit, priority, or line count to troubleshoot system issues.
Get recent system logs from journalctl (Linux only)
| Name | Required | Description | Default |
|---|---|---|---|
| unit | No | Filter by systemd unit (e.g., 'docker', 'nginx') | |
| lines | No | Number of log lines to return (default: 50) | |
| priority | No | Minimum log priority level |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden of behavioral disclosure. It communicates a read-only intent ('Get'), the source ('journalctl'), and the platform limitation ('Linux only'), but it does not mention potential permission requirements, large output, or behavior if journald is unavailable. Adequate but not detailed.
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?
The description is one short, front-loaded sentence with no filler. The parenthetical 'Linux only' adds a valuable constraint without wasted words, and every element contributes to understanding the tool.
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 read-only log tool with three optional, fully documented parameters, the description plus schema is mostly complete. It identifies the source and platform, and the schema covers defaults and filters; however, without an output schema, the exact return shape is left slightly implicit.
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 the schema already explains unit, lines, and priority, including the priority enum. The description adds no parameter-level meaning beyond the vague word 'recent', which does not clarify the default line count or filter semantics.
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 names a specific action ('Get'), resource ('system logs'), and mechanism ('journalctl'), plus the platform constraint ('Linux only'). This clearly differentiates it from siblings like list_processes and get_docker_status, which address different system aspects.
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 the tool is for retrieving systemd journal logs and restricts usage to Linux, but it does not explicitly explain when to choose this tool over the sibling tools or when not to use it. The usage context is inferable but not directly stated.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.