pix_open_capture

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

Annotations already provide idempotentHint=true and readOnlyHint=false, and the description adds no further behavioral context such as whether the capture is loaded into memory, whether repeated calls return an existing capture_id, or whether remote paths trigger network activity. No contradiction with annotations, but no additional transparency either.

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, front-loaded sentence with no filler; it efficiently conveys the core action and return value. The conciseness is fine, though it comes at the expense of substantive guidance.

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 9 parameters, zero schema coverage, and no usage context, this one-line description is far from complete. The output schema may cover the return value, but input semantics, prerequisites, and optional parameter triggers are entirely opaque. It provides only surface-level registration context.

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%, and the description names no parameters or constraints. It only mentions the output capture_id, leaving capture_path, remote, prefetch, timeout_seconds, and the GPU options entirely unexplained. The description does not compensate for the schema gap.

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 action ('register a capture') and the return contract ('capture_id plus a compact overview'). This is distinguishable from close/list/get-overview siblings by the registration action, though 'register' is slightly ambiguous about whether it means opening an existing capture or creating a new one.

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?

No guidance on when to use this tool versus pix_capture_* for creating captures, pix_close_capture for closing, or pix_get_capture_overview for inspecting an open capture. The name implies opening an existing capture, but the description never states the prerequisite or names alternatives.

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