qemu_screen_capture

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

Annotations already declare the operation as read-only, idempotent, and non-destructive, and the description adds a useful timing constraint rather than contradicting them. However, it does not explain behavior if the controller has already started, whether the VM must exist, or what the capture output looks like, so it adds only modest context beyond the annotations.

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 a single, front-loaded sentence with no filler or redundancy. It communicates the essential verb, resource, and timing condition efficiently.

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?

For a one-parameter, read-only capture tool, the core information is present and the annotations cover the safety profile. The main gaps are the undefined 'Windows controller' term, the lack of any return-format hint, and no mention of failure modes; with no output schema, the description must carry more of this burden.

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 0%, but the description never mentions vm_id or explains that it identifies the target VM. The parameter name and pattern provide some inference, but with low schema coverage the description should explicitly tie vm_id to the framebuffer being captured; it does not.

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 states a specific action ('capture') and resource ('QEMU framebuffer'), with a temporal qualifier that distinguishes it from generic siblings like screen_capture or window_capture. However, the phrase 'Windows controller' is not defined and no sibling is explicitly contrasted, so it stops 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 description provides clear context: this tool is for capturing the QEMU framebuffer before the Windows controller has started, which implies a pre-boot or early-boot scenario. It does not explicitly name alternatives or say when not to use it, but the timing condition is concrete enough to guide selection over generic screen capture tools.

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