unit_file

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

Beyond the annotations' readOnlyHint/openWorldHint, the description discloses redaction, a hard 65536-byte cap, the [TRUNCATED] sentinel, and that the truncated flag flips to true on a cut. That is genuinely useful operational context. It stops short of explaining why redaction occurs or whether scope affects which file is read.

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 compact sentences, front-loaded with the identity of the returned content, followed by the caveats. Nothing is padded and every clause adds information.

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?

An output schema exists, so return-shape detail is not strictly required, and the truncation flag is still usefully surfaced. However, with two undocumented required parameters at 0% schema coverage, the definition is not complete enough for confident invocation.

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?

Both required parameters, unit and scope, have zero schema description coverage, so the description carries the full burden and fails it. It never explains what 'unit' should contain (name, instance, suffix?) or what values 'scope' accepts (system vs user), leaving an agent to guess at invocation.

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 specific resource (the unit file text) and anchors it to a familiar reference ('as systemctl cat prints it'), which tells an agent exactly what content comes back. It does not differentiate itself from siblings like unit_status or list_units, which also concern units, so an agent must infer the distinction.

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 never says when to reach for this tool versus unit_status, list_units, or journal. 'Read-only' is the only routing hint, and it is already covered by annotations, so there is effectively no usage guidance.

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