get_webcam_snapshot

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered, but the description goes further by naming the failure mode ('frame_too_dark'), the hardware reason for it (case light off when the touchscreen sleeps), and the remediation call. The warning that frames returned with allow_dark=true must never be described is a meaningful disclosure the annotations could not convey. It does not mention latency, image format, or capture timing, leaving some behavioral gaps for an open-world capture tool.

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?

Three sentences, front-loaded with purpose, then use case, then the dark-frame caveat — no filler. The final sentence is long and carries two distinct instructions (allow_dark semantics and the do-not-describe rule), which slightly reduces scannability.

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 and no annotation coverage of failure behavior, the description correctly invests in the error path and the remediation sequence, which is what an agent needs to call this successfully. The remaining gap is camera_url, which is neither explained nor linked to list_webcams.

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% for both parameters, so the description must compensate entirely. It fully explains allow_dark's purpose and consequence ('only if you want the raw bytes regardless'), but camera_url is never mentioned, leaving the agent to guess how it relates to the sibling list_webcams tool or what happens when it is omitted.

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?

Opens with a specific verb and resource ('Grab a still image from the printer's camera') and immediately distinguishes itself from the sibling list_webcams by emphasizing it returns the frame for inspection rather than enumerating cameras. The follow-on use case ('check on a print: whether the first layer stuck...') makes the tool's role unmistakable.

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?

Gives concrete when-to-use conditions (first-layer adhesion, spaghetti, part detachment) and explicitly names the alternative path when the frame is dark: call set_case_light first rather than retrying. It also states the precise condition for the allow_dark escape hatch and warns not to interpret frames obtained that way, which is exactly the when-not guidance an agent needs.

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