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

Annotations already declare readOnlyHint, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds that this is static "house rules" content read once, which usefully signals cacheability and zero side effects. It does not describe the shape or size of the returned guidance, so the added behavioral context is modest.

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, no filler. The content enumeration comes first and the usage instruction is front-loaded at the end, so an agent can decide and act after a single pass.

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?

With no input schema and no output schema, the description carries the burden of saying what comes back, and it does so by listing the categories of guidance. The remaining gap is relational: it never positions itself against get_motion or search_motion, which an agent will see in the same tool list.

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?

The tool takes zero parameters and the schema is empty, so there is nothing for the description to disambiguate. The baseline for a no-param tool applies, and nothing in the description misleads about inputs.

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 names a specific resource and enumerates its contents (durations, enter/exit easing, springs, reduced motion, tokens, categories, triggers), so an agent knows exactly what it gets back. It does not, however, distinguish this reference document from the sibling tools get_motion and search_motion, which sound like they cover adjacent territory.

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?

"Read it once before adding animation" gives a clear, actionable trigger and implies the tool is a one-time priming read rather than a per-task call. It stops short of naming alternatives (get_motion, search_motion) or saying when this static reference is insufficient and a search tool is needed instead.

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