set_render_passes

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

No annotations exist, so the description carries the burden. It discloses the mutation and that it targets the active view layer, lists which passes are engine-restricted (Cycles, EEVEE), and states the return shape. It does not say what happens when a pass is unsupported by the current engine, or whether changes persist to render settings vs. view-layer only — a real gap for a mutation tool with zero annotation coverage.

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 purpose is front-loaded in the first sentence and the definition follows. The long pass enumeration is justified because the schema has no enum, though the prose middle sentence ('depth for fog and focus, mist, normals...') is illustrative rather than operational and could be trimmed.

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?

An output schema exists, so return values need only light mention, which the description provides. Given only two parameters and a docstring-style layout, it covers the essentials, though the missing error/precondition behavior for engine-incompatible passes keeps it short of complete.

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 fully compensates: it enumerates all valid pass names including aliases (z/depth, ao/ambient_occlusion, emit/emission) and flags engine-specific ones. The 'enabled' boolean is also explained ('True to turn them on, False to turn them off'), including its default semantics.

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 verb and resource plus scope: 'Turn render passes on or off for the active view layer.' The follow-up sentence explains what passes are (multilayer EXR, compositor channels), so the agent knows what is being toggled. It does not name the nearest alternative (manage_aov, setup_compositor), so sibling differentiation is left to inference.

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?

Context is implied by 'for the active view layer' and by the EXR/compositor framing, but there is no explicit when-to-use, when-not-to-use, or pointer to a competing tool such as manage_aov for arbitrary AOVs. The engine caveats (Cycles/EEVEE) on individual passes are useful but describe availability, not selection guidance.

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