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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), so the bar is lower. The description adds real context beyond that by enumerating the payload — tabs, focused tab, last report, remaining allowance, prices — telling the agent this single call returns a full snapshot rather than a partial list.

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 tight sentences, with the core action front-loaded and the payload summary following. Every clause earns its place; there is no filler or repetition of the title.

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 usefully summarizes what is returned, which is a strength. But it omits any auth/permission expectations for guest_token and offers no guidance on refresh or failure behavior, leaving gaps for a required-token tool.

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 single required parameter guest_token has 0% schema description coverage, so the description must compensate, and it does not define or explain the token. The parenthetical "(guest or session)" only indirectly gestures at the guest/session distinction without clarifying the parameter's role.

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 ("Lists the owner's tabs") and scopes it to guest or session context, so it is clearly distinct from siblings like create_tab, run_tab, and tab_history. It stops short of explicitly naming an alternative, but the verb+resource is unambiguous.

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?

Usage is only implied: "One call draws the whole screen" hints that this is the broad fetch-everything call, which helps an agent choose it over narrower tools. However, no when-to-use/when-not conditions or alternative tool names are given.

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