Journal tail

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

Annotations already declare this is a safe, idempotent read operation, and the description adds meaningful behavioral context: control-character cleaning, masking of secret-looking values, and a prompt-injection warning about machine-authored text. It does not cover error behavior or truncation limits, but the safety disclosure is well above the annotation baseline.

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 three tightly written sentences that front-load the purpose and then add security-relevant context. Every sentence earns its place, including the injection warning.

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 the rich annotations, full schema descriptions, and an output schema, the description covers the essential behavioral context an agent needs to invoke it safely. The main gap is that it does not clarify how it relates to sibling log-reading tools.

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 all four parameters are already documented in the schema. The description maps to the same filters at a high level but adds no syntax, defaults, or constraints beyond what the schema provides, making the baseline 3 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 states a specific resource and scope: the latest systemd journal lines, optionally filtered by unit, priority, and time window. It is clear what the tool returns, but it does not explicitly distinguish itself from sibling tools like list_logs or read_log.

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 implied by the 'latest ... optionally ... last N minutes' framing, which suggests tailing recent logs. However, there is no explicit when-to-use or when-not-to-use guidance, and no sibling alternative is named.

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