Read the first N lines of a file, automatically decompressing .gz formats (FASTQ, VCF, BED) for quick data inspection on an HPC cluster.
First N lines of a file. Transparently decompresses .gz files (FASTQ, VCF, BED, …).
| Name | Required | Description | Default |
|---|---|---|---|
| path | Yes | Absolute path on the cluster | |
| lines | No |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already establish the safe read-only profile (readOnlyHint=true, destructiveHint=false, openWorldHint=false), so the bar is lower. The description adds genuinely useful behavior beyond that: it transparently decompresses .gz files across FASTQ/VCF/BED, which saves the agent from pre-decompressing. It does not state truncation/return format, but the added decompression context is meaningful.
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?
Two short sentences, zero filler, with the core operation front-loaded and the decompression caveat immediately following. Nothing needs to be cut or reordered.
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 read-only preview tool with no output schema, the description covers what the tool does and its key non-obvious behavior (gz decompression). The only minor gap is that it does not describe the return shape or whether output is truncated by line length, which is acceptable given the tool's simplicity.
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 coverage is 50%: path is documented as an absolute cluster path, while lines only carries a default (50) and maximum (1000) with no prose. The description's "First N lines" loosely maps N to the lines parameter but adds no syntax or behavior detail beyond the schema. Baseline 3 is appropriate.
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 gives a concrete verb+resource ("First N lines of a file") that an agent can immediately map to the head operation, and the explicit gz-decompression scope further pins down behavior. It does not name sibling tools such as hpc_tail_file or hpc_read_file, so the differentiation from alternatives is left implicit rather than stated.
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: an agent can infer this is the tool for peeking at the beginning of a file, and the .gz note signals it is safe for compressed genomic formats. There is no explicit when-to-use statement and no guidance on when to prefer hpc_read_file, hpc_tail_file, or hpc_search_in_file instead.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.