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

Annotations already declare this read-only, idempotent, non-destructive and open-world, so the safety profile is covered. The description adds value by effectively enumerating the return payload (a full host fact sheet), which matters because there is no output schema, and by asserting it should be the first call. It omits auth requirements and rate/performance notes, so this is not a 5.

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 sentences with zero waste: the data enumeration is front-loaded so the agent sees scope first, and the actionable directive ('call this first') lands last. Nothing needs trimming.

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 output schema, the description's list of returned facts is exactly the compensation needed. Safety is handled by annotations and the lone optional parameter is fully documented, so only minor workflow details (e.g., what to do with the results) are absent.

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% and the single `server` parameter is already documented as optional when the account has one server. The description adds no additional meaning about accepted server identifiers or fallback behavior, so baseline 3 applies.

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 enumerates the exact inventory returned (distro, kernel, CPU, memory, disk, package manager, services, listening ports, CMS installs), which is far more specific than the tautological title 'Server facts'. It is clearly distinguishable from siblings like list_servers, overview, or health_report because it names the specific host-level data it produces. The verb is implicit ('call this' implies report/return), which keeps it just 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?

The closing instruction 'Call this first on a server' gives explicit ordering guidance for the agent's workflow. No alternative tools are named or excluded, so it stops short of a 5, but the when-to-use condition is unambiguous.

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