pix_save_resource

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

Annotations already indicate the operation is non-read-only, idempotent, and non-destructive. The description adds valuable behavioral context beyond annotations: the output format is determined by the destination extension, and event selection falls back to the last bound event when global_id or marker is omitted. There is no contradiction with 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 concise and well-structured: the first sentence states the core purpose, and the second adds important file-format and selection fallback details. Every sentence earns its place with no filler or redundant restating of the tool name.

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?

The description covers the essential behavior and the non-obvious fallback selection logic, and an output schema exists to describe return values. However, with 7 parameters and no schema descriptions, more detail about required capture_id, destination semantics, and timeout_seconds would be needed for fully confident invocation. It is adequate but has clear gaps.

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%, so the description must compensate for the 7 undocumented parameters. It provides semantic hints for rtv, depth, global_id, marker, and destination, but it does not clarify capture_id, timeout_seconds, or the exact meaning/format of destination beyond extension-based format. The coverage is too partial for a schema with no property descriptions.

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 ('Save') and a specific resource ('a bound resource (render target or depth buffer) from a draw call'), which clearly identifies the tool's purpose. It does not explicitly name sibling tools or how it differs from pix_save_screenshot or pix_get_resource, but the resource type and draw-call context make the purpose reasonably distinct.

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 implies when to use the tool: when you need to save a bound render target or depth buffer from a draw call. It also gives a useful selection rule about global_id/marker and the fallback to the last bound event, but it does not explicitly state when to prefer this tool over alternatives like pix_save_screenshot or pix_get_resource.

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