Read recent lines from a log or text file safely, with optional regex filtering to isolate errors or events without loading the whole file.
Safely read recent lines from a log or text file with optional regex filtering.
| Name | Required | Description | Default |
|---|---|---|---|
| lines | No | Number of recent lines to retrieve (default: 50, max: 500) | |
| pattern | No | Optional regex pattern to filter lines | |
| filepath | Yes | Absolute or relative path to log file |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden. 'Safely read' signals a non-mutating operation, which is useful, but it says nothing about error behavior (missing file, permission denied), how large files are handled, or what the output looks like.
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 front-loaded sentence with the core action and scope first and the optional capability trailing. No filler or repetition.
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 three-parameter read tool with full schema coverage, the description covers the essentials. However, with no annotations and no output schema, it leaves error handling and result shape unexplained, which is a meaningful gap.
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 defaults, maximums, and per-parameter meaning are already documented. The description only echoes the optional regex filtering, adding no syntax or format detail 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 concrete verb ('read') and resource ('recent lines from a log or text file') with the regex filtering capability, so the agent knows exactly what it does. It is clearly distinct from the systemd/resource inspection siblings, though it never names them explicitly.
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?
Usage is only implied by the resource type (log/text files); there is no explicit when-to-use, when-not-to-use, or alternative routing. 'Recent lines' hints at tail-style inspection, but the agent must infer the context itself.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.