Result toggle playback

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

Annotations already declare the full safety profile (readOnlyHint=false, idempotentHint=false, destructiveHint=false), and the description essentially restates the tool name without adding anything. It doesn't disclose what happens if no animation is loaded, whether toggling has side effects on a running simulation, or any preconditions. With annotations present the bar is lower, but this sentence contributes nothing beyond the name.

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?

One front-loaded sentence with no waste. It is efficient, though it is so terse that it borders on under-specification rather than earning full marks for structure.

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 no-param, no-output-schema control tool this is the minimum viable level. It omits preconditions (a loaded result, a selected view) and the relationship to the adjacent playback/time tools, which an agent would need to invoke it confidently.

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, so there is nothing for the description to disambiguate. Per the rubric, a 0-parameter tool baselines at 4.

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: 'toggle play/pause of the result animation.' That cleanly distinguishes it from siblings like result_set_playback_speed or result_set_time, which modify parameters rather than flipping play state. However, it never explicitly names those siblings, 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 at all. The description doesn't say whether a result must already be loaded, whether this acts on the active view or all views, or how it relates to result_set_time/result_set_playback_speed. The agent is left to infer the calling context.

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