timeline_roll_to

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

With no annotations at all, the description carries the full burden and does so: it discloses that features created by other tools land at the marker position and evaluate against the rolled-back model, that rolling into a collapsed group expands it, and that the marker should be restored to 'end'. These are non-obvious, high-consequence side effects an agent could not infer.

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 core action and consequence, and every sentence carries information. The WARNING block is dense and the awkward line-breaks/quoting around 'end' add minor noise, but nothing is padding.

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?

There is no output schema, and the description compensates by listing the returned keys. For a mutation-style tool with two parameters and no annotations, everything an agent needs to call it and to clean up afterward is stated.

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 baseline is 3; the description earns a bump by demonstrating the coupling in practice — position="before" with an item ref — and by naming the return keys, which the schema does not cover. It still does not explain what an 'item ref' string looks like beyond the example.

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?

Names a specific verb+resource ('Move the timeline marker') and immediately states the consequence ('Items after the marker are rolled back'), which makes it unmistakable against siblings like timeline_set_suppressed, timeline_delete, or timeline_compute_all.

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?

Gives a concrete usage scenario in the example (roll 'before' an extrude, add a feature, then roll to 'end') and an explicit conditional recommendation to return the marker to 'end'. It stops short of naming alternative timeline tools or stating when not to use this one, so it is strong but not exhaustive.

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