system_summary

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

Annotations already declare readOnlyHint=true and openWorldHint=false, and the description merely restates 'Read-only', which adds no new safety information. It does add useful scope context by enumerating exactly which data points are returned, but omits anything about caching, staleness, or refresh behavior for a summary snapshot.

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 dense sentence with no filler, and it leads with the primary resource (the system manager's state). 'Both managers' is left unexpanded, which forces a small inference, but the description is otherwise tight and front-loaded.

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 no inputs and an output schema present, the definition has little left to carry, and the field enumeration is sufficient for an agent to select it. It would be fully complete with one clause routing the agent away from the per-unit sibling tools when only aggregate counts are needed.

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?

The tool takes zero parameters, so the baseline is 4. The description's enumeration of returned fields is not parameter semantics, but nothing is required of it here beyond confirming the absence of inputs.

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 names a specific aggregate resource — the system manager's state word, failed-unit and timer counts for both managers, and the boot's first-entry time — so an agent knows this is a roll-up view rather than a listing. However, it never differentiates itself from siblings like failed_units, list_timers, or unit_status, which appear to return the same underlying data at finer granularity.

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 when-to-use or when-not-to-use guidance. The word 'summary' implies an overview role, but the description never states that an agent should prefer this over calling list_units/list_timers when it only needs counts, nor does it list any prerequisite.

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