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

Annotations flag destructiveHint=true and idempotentHint=true, but the description is what explains why: reloading the tab kills any export or render in progress. That is exactly the kind of consequence an agent cannot get from the annotation flags alone, and it justifies the destructive hint rather than contradicting it.

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?

Three short sentences, front-loaded with what the tool does, then the 'not required' caveat, then the one harmful side effect. No filler and the risk is stated last for emphasis.

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 two-parameter tool with annotations and no output schema, the description covers purpose, necessity, and the destructive side effect. It omits edge behavior such as whether a tab is created if none is open, or what the caller sees on success — minor gaps only.

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 both parameters are self-documenting (token identifies the browser session, projectId comes from get_projects). The description adds no parameter-level detail beyond the schema, so baseline 3 applies.

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?

States a specific verb and resource — navigating the user's Frapea tab to a project — and clarifies the intent is passive viewing ("WATCH the edit live"). It doesn't explicitly contrast with close_project/open_timeline/set_active_timeline, so an agent must infer the boundary from the "headless editing" framing.

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 an explicit when-not ("Not required for editing — every tool works headlessly") and an explicit when ("use this for show-your-work moments"). The agent knows both that skipping this tool is safe and the condition that makes calling it worthwhile.

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