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

Goes well beyond the annotations (which already declare readOnly/idempotent/non-destructive): it discloses that stopping with nothing shared is a success not an error, that the return is presenting=false, and critically that ok=false means the share may STILL BE UP with retry/present_status guidance. This is exactly the failure-mode context an agent needs.

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?

Purpose is front-loaded, and every subsequent sentence carries distinct value (alternatives, idempotent-success semantics, return value, failure handling). It runs long, but the density of unique information justifies the length rather than 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?

With no output schema, the description correctly compensates by explaining both the success return (presenting=false) and the failure signal (ok=false, share still up) plus the follow-up tool. For a 1-param mutation-of-share-state tool, an agent has everything needed to call it and interpret results.

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 in_workspace is already fully documented in the schema, and the description adds no format or semantics beyond it. The phrase 'Takes no arguments' is about the absence of required targeting args but slightly understates the optional in_workspace override; baseline 3 is appropriate when the schema does the heavy lifting.

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 precise verb+resource ('take whatever is on the call's screen-share back down, so the room sees nobody presenting') and scopes it to THIS call. It explicitly distinguishes itself from siblings present_tab and browser.close, so an agent can pick correctly without opening any 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 explicit when-to-use ('when you are done with a tab and the room should stop looking at it') plus named alternatives with the condition that selects them: present_tab with a different page_id switches the share, browser.close on the shared tab also ends it. Nothing is left to inference.

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