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

Annotations already declare readOnlyHint=false, destructiveHint=false, and idempotentHint=true, so the base behavioral safety profile is covered. The description adds useful batch context ('several widgets at once' and 'whole view'), but it doesn't disclose whether unspecified widgets are preserved or whether layouts are fully replaced. No contradiction with annotations exists.

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 exactly two sentences with no filler. The primary action and grid constraint are front-loaded, and the usage alternative is stated economically in the second sentence. Every word earns its place.

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?

For a batch layout mutation with two well-documented parameters and no output schema, the description provides sufficient context: what the tool does, when to use it, and the grid model. The main missing piece is a note on response behavior or error semantics, but that is minor given the simplicity and rich schema.

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 coverage is 100%, and the schema already contains meaningful descriptions for both parameters, including the grid constraints on x/y/width/height. The description reinforces the 12-column grid concept but does not add substantive parameter-level detail beyond the schema, so the baseline score of 3 is appropriate.

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 ('Reposition'), a clear resource ('several widgets on a view'), and a key constraint ('on the 12-column grid'). It also distinguishes itself from the alternative of moving widgets one at a time, which directly separates it from sibling tools like update_widget.

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 'Use this to lay out a whole view rather than moving widgets one at a time,' which provides clear when-to-use guidance and contrasts against a single-widget alternative. However, it does not name the alternative sibling tool explicitly, so it falls just short of a perfect 5.

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