Check for System Updates

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

Annotations already declare readOnlyHint=true and openWorldHint=false. The description adds useful behavioral context by specifying that the tool reports the current version, candidate version, release notes, and reboot waiting status. It also clarifies scope limitations (no app updates). No contradictions with annotations exist.

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 sentences, front-loading the primary action, followed by output details and a scope note. Every sentence contributes meaningful information with no redundancy or fluff.

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 tool's simplicity (1 optional parameter, output schema exists, annotations present), the description is complete: it states what is checked (update availability, reboot pending), what is reported (versions, release notes), and what is excluded (app updates). This is sufficient for an agent to correctly select and invoke the tool.

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 100%. The single parameter 'response_format' is fully documented in the schema with enum values and descriptions. The tool description adds no additional parameter semantics, so the baseline of 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 clearly states the tool's function: 'Check whether a TrueNAS base-OS (system) update is available, and whether the system is waiting on a reboot.' It specifies the resource (TrueNAS OS) and distinguishes itself from app/catalog updates, making it distinct from sibling tools like truenas_list_apps. It also enumerates the key outputs (current version, candidate version, release notes).

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 provides an explicit exclusion: 'this covers the TrueNAS OS only — it does NOT check for app/catalog updates,' which constitutes a clear when-not-to-use. The context for when to use is implied by 'Check whether... update is available.' However, it does not name an alternative tool, so it falls short of a full 5.

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