Linux MCP Server

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

With no annotations provided, the description carries full burden for behavioral disclosure. While it mentions SSH connectivity behavior (remote vs local execution), it doesn't describe what specific filesystem usage information is returned, format of output, whether it requires special permissions, potential performance impact, or error conditions. The description provides some context but leaves significant behavioral aspects unspecified.

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 appropriately sized with a clear purpose statement followed by parameter documentation. The two-sentence structure is efficient, though the parameter documentation could be slightly more integrated with the main description rather than appearing as a separate 'Args' section.

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?

Given that an output schema exists (which should document return values), the description doesn't need to explain return values. However, for a system monitoring tool with no annotations and 2 parameters, the description should provide more behavioral context about what specific disk usage metrics are retrieved, typical use cases, or limitations. The SSH connectivity details are helpful but insufficient for full completeness.

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?

With 0% schema description coverage, the description must compensate for the schema's lack of parameter documentation. The description successfully adds meaningful semantics for both parameters: it explains that 'host' is optional for remote SSH connections (defaulting to local execution), and that 'username' is required conditionally based on whether host is provided. This provides crucial context beyond the bare 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?

The description clearly states the tool's purpose with specific verbs ('Get filesystem usage and mount points'), which distinguishes it from sibling tools focused on CPU, memory, network, or logs. However, it doesn't explicitly differentiate from 'list_block_devices' which might provide related but different information about storage devices.

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 context through the parameter documentation (SSH for remote hosts, local execution if no host provided), but doesn't explicitly state when to use this tool versus alternatives like 'list_block_devices' or other system monitoring tools. No explicit when-not-to-use guidance or named alternatives are provided.

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