Load browser state

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

Annotations only flag destructiveHint=true; the description adds the crucial scope of that destruction (which stores are overwritten), a non-obvious carve-out (sessionStorage and open tabs untouched), and the follow-up needed for the restoration to take effect. That is exactly the kind of detail structured fields cannot convey.

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 sentences, zero filler. The primary effect is front-loaded and the caveats/follow-up immediately follow it.

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 mutation tool with rich annotations and no output schema, the description covers what changes, what doesn't, and what the agent must do next. What remains unstated is behavior on error or a missing/invalid state file, which is a modest gap.

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%, with path and session_id fully documented in the schema. The description contributes only one extra semantic detail, the file being Playwright-compatible, which is minor additional meaning; the schema does the heavy lifting as expected.

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 ('Replace') plus the exact resources affected (cookies, local storage, IndexedDB) and the source format (Playwright-compatible JSON file). This is clearly the inverse of browser_save_state, so an agent can distinguish the pair from the text alone.

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?

'Fetch or reload pages to use the restored login' tells the agent what must happen after the call, and 'Leaves sessionStorage and open tabs unchanged' defines the boundaries of what this call restores. It stops short of explicitly naming browser_save_state as the counterpart or stating when not to use this, so it falls just short of full routing guidance.

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