Select layers

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

Beyond readOnlyHint=false, the description reveals that selection is persistent state consumed by other tools and that it is a mutating operation on that state. No contradiction with annotations. It does not discuss whether selection is replaced vs merged, but 'Change' plus schema's deselect behavior keeps this adequate.

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?

Two sentences with no filler. The action word is front-loaded, and the second sentence earns its place by explaining cross-tool consequence.

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 tool with two optional params, full schema descriptions, and no output schema, the description covers the important operational concept (selection as fallback). A fully explicit statement that selection replaces any prior selection, and layer identifier formats, would push it to 5, but these are inferable.

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%, so the parameters carry their own meaning (comp and layers/deselect). The description does not add parameter-level detail; it only reinforces the high-level selection concept. Baseline 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 first sentence names a concrete action and object: 'Change the timeline selection.' The next sentence positions it in the workflow ('Other tools fall back to the selection when you omit `layer`'), which distinguishes it from the sibling layer/property tools and explains why this tool exists.

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?

It gives clear usage context: select once so later commands that omit layer apply to the chosen layers. It does not enumerate which siblings are affected or state when to bypass this tool and pass layer directly, so it stops short of explicit when-not/exclusion guidance.

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