Read Device Journal

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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is fully covered by structured data. The description only restates the read operation and adds no extra behavioral context such as output shape, streaming/pagination behavior, or what happens when the device is unreachable.

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 short sentence, front-loaded with the essential verb and resource, with no filler. It is appropriately sized but arguably too terse for a six-parameter tool.

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?

With six parameters, only one required and low schema coverage, plus no output schema, the description is too thin. An agent gets no sense of return format, default windowing ('recent' is unquantified), or how grep/unit/since interact with the defaults.

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 only 33% (device and timeout are documented, grep/unit/lines/since are not), and the description supplies no parameter meaning at all. It doesn't explain grep semantics, unit filtering, line limits, or the since time format, so it fails to compensate for the coverage gap.

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?

Specific verb + resource: reads journalctl output from a Sailfish OS device. It's clear what the tool does and reads distinct from siblings like sailfish_device_command_start or sailfish_device_topmost_pid. It doesn't explicitly differentiate itself from other log-adjacent siblings, so it falls short of a 5.

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?

There is no statement of when to use this tool versus alternatives. The user might equally well run journalctl via sailfish_device_command_start or sailfish_device_user_session_command, and nothing tells the agent why to choose this one. No prerequisites or exclusions are mentioned.

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