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

Annotations already declare readOnly/idempotent/non-destructive, but the description adds real behavioral context beyond them: it clarifies that pressing keys or scrolling does NOT change the shared tab, only present_tab does. It reads the state live from the shared tab, which explains why it is a safe, side-effect-free check.

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 front-loaded sentences with zero waste: what it reads, what it returns, and the caveat about tab switching. Emphasis on 'ACTUALLY' signals the point-of-truth framing efficiently.

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?

Even without an output schema, the description enumerates the return fields, and annotations cover the safety profile. For a read-only status check with one optional param, nothing an agent needs to call it correctly is missing.

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?

With a single optional parameter at 100% schema description coverage, the schema already documents in_workspace fully; the description adds nothing about it. Baseline 3 is appropriate since the schema carries the parameter semantics.

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+resource ('Ask what the room is ACTUALLY seeing on the screen-share') and enumerates the returned fields (presenting, page_id, url, title). It explicitly distinguishes itself from the sibling present_tab, so an agent can route without opening either schema.

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 concrete triggers ('before telling participants what is on screen', 'whenever you are not certain the share still points at the tab you meant') and names the alternative that changes the shared tab. The when-to-use is explicit and tied to a named sibling.

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