set_motion_blur

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

With no annotations, the description must carry the full behavioral load. It does disclose that this is a mutating setter ('after the change') and notes engine applicability for eevee_steps, which is genuinely useful. However, it never explains the semantics of the nullable defaults — every parameter is optional and defaults to null/empty, yet the description doesn't say whether omitting a param leaves the existing setting untouched or resets it, and it doesn't mention what other motion-blur-adjacent settings (e.g., rolling shutter, deformation blur) may be affected.

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?

Front-loaded with the one-line purpose, then a compact per-argument block with no filler. The trailing 'Returns' line is slightly redundant given an output schema exists, but it is a single sentence and doesn't bloat the definition.

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 return value is covered by the output schema, so omitting return detail is acceptable. But for a four-parameter, zero-required, zero-annotation mutation tool, the missing partial-update semantics (what happens when a param is null) is a real hole an agent could get wrong — it may assume unspecified fields reset to defaults.

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, and it largely does: all four parameters get meaning plus numeric ranges (shutter 0.0–2.0, eevee_steps 1–64), a concrete calibration example ('0.5 is a film-like 180 degree shutter'), enum semantics for position, and engine scoping for eevee_steps. The only shortfall is the unexplained null/omitted-value behavior, which is central to how this all-optional tool is invoked.

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 ('Set render motion blur for moving objects and cameras'), which is unambiguous and clearly distinct from render-family siblings like set_denoising, set_film or set_render_samples. It does not explicitly name any sibling it competes with, so it stops short of a 5.

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?

Usage is implied rather than stated: the agent must infer this is the tool for render-time motion blur setup. There is no when-to-use/when-not guidance and no alternative named (e.g., per-object motion blur vs camera blur, or which render engine this applies to). The 'EEVEE only' note on eevee_steps is the only scoping hint.

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