set_fixed_children

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

With no annotations, the description carries the full burden. It does disclose the effect ('fix position when scrolling') and the non-recursive scope ('direct children'), which is useful. However, it says nothing about whether the call replaces or extends the existing fixed set, whether it requires the frame to already scroll, or whether it is reversible — critical for a mutation tool.

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, and the core action comes first. The trailing parenthetical restates the same idea in different words, which is mild redundancy rather than waste.

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?

This is a mutation tool with no annotations, no output schema, and no parameter documentation; the description should therefore do more. It omits idempotency/replacement semantics, prerequisites on the parent frame, and any indication of the result of the call.

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 never mentions either parameter. It is unclear whether fixedChildIds is a full replacement list or additive, and whether frameId must reference a scrolling frame. Parameter names are self-suggestive, which keeps this above a 1, but the description adds no meaning beyond the schema.

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 verb and resource: 'Mark direct children of a frame as fixed in a scrolling prototype,' and the parenthetical clarifies the effect. It does not differentiate from adjacent prototype/scroll siblings such as set_overflow_direction or set_keyframe_track, 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?

There is no when-to-use guidance, no mention of prerequisites (e.g. the frame must have scrolling overflow set), and no reference to alternative or complementary tools. The agent must infer the entire workflow context from the name.

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