list_guests

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

Beyond readOnlyHint=true, the description discloses that the tool never contacts guests, that permissions are derived from Proxmox tags, and that source='static-config' signals a disconnected Proxmox with config-sourced guests. The last point preempts a likely false-positive error interpretation, which is exactly the context annotations cannot convey.

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?

Front-loaded with purpose and returned fields, then the entry-point guidance, then the caveat about static-config. Four dense sentences with little waste, though the tag-permission parenthetical and the source explanation could be tightened slightly.

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?

An output schema exists, yet the description still flags the one thing an agent would misread as a failure (source='static-config'). Combined with the entry-point framing and no parameters to document, nothing needed to call this correctly is missing.

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?

There are zero input parameters, so baseline is 4. The description's detail about tags and permission flags describes output fields rather than inputs, which is useful but not parameter semantics.

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?

States a specific verb and resource ("List guests pvewarden can see") and enumerates exactly what comes back: VMID, name, status, tags and permissions. The parenthetical tag-to-permission mapping (may_update/may_reboot) makes the result shape unambiguous and separates it from siblings like check_updates.

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?

"Start here: it is how you find the VMIDs the other tools take" explicitly positions this as the entry point for the toolset. It also names the alternative for a related concern ("Does not contact the guests; check_updates does"), giving both when-to-use and when-not-to-use guidance.

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