pix_run_pixtool

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

The description adds important runtime behavior beyond the annotations: pixtool aborts remaining commands once one fails, null option values become bare flags, values with spaces are quoted automatically, and double quotes cannot be expressed. These are non-obvious and not covered by readOnlyHint or destructiveHint.

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?

Every sentence earns its place: purpose, escape-hatch positioning, command object format, null-option handling, capture prefix, failure semantics, and quoting edge cases. It is dense but well-organized and front-loads the core description without redundancy.

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 is very complete for an open-world escape hatch: it covers command structure, failure behavior, quoting, capture prefix, and gives a concrete example. The only minor gap is the semantics of output_level and timeout_seconds, which are optional and not required for basic invocation. The presence of an output schema reduces the need to describe return values.

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?

For a tool with 0% schema description coverage, the description compensates well for 'commands' (list of objects with name, positionals, and options) and for 'capture_id' (prepends open-capture). However, it says nothing about 'output_level' or 'timeout_seconds', leaving those optional parameters without added meaning beyond their titles, which is a clear 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?

The first sentence states a specific action: 'Run an arbitrary pixtool command pipeline.' It also explicitly labels itself as the escape hatch for pixtool features without a dedicated tool, which distinguishes it from the many sibling pix_* tools and clarifies its unique role.

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 explicitly says this tool is for pixtool features 'without a dedicated tool', giving a when-to-use versus when-not-to-use rule. It also provides a concrete invocation structure with an example and explains the capture_id prefix behavior, so an agent knows exactly how to construct a call.

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