session

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

Annotations only supply openWorldHint=false, so the description carries most of the burden and does disclose meaningful traits: launch discards open tabs but cookies survive in a persistent profile, and close behaves differently across launch and attach modes. It stops short of covering failure modes or what happens to an existing session on relaunch.

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?

A single dense sentence that front-loads the resource and enumerates actions with their consequences; every clause carries information. The nested parentheses make it slightly harder to scan than a short bulleted form would be.

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?

There is no output schema, and the description nevertheless enumerates what status returns (mode, headless, browser version, profile, tabs, active tab). For a three-action lifecycle tool with thin annotations, this covers what an agent needs to invoke it correctly.

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 40%, so the description must compensate, and it does explain the action enum values and the launch-vs-attach distinction for mode. However, headless, isolated, and cdp_endpoint are left to the schema (only the latter two are documented there), so the gap is only partially filled.

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?

The description names the resource (browser session) and spells out the three action values with their distinct effects: status reports mode/headless/version/profile/tabs, launch restarts the browser, close ends or disconnects. An agent can distinguish this lifecycle tool from siblings like tabs or navigate without opening the 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?

It gives per-action conditions ('close the browser in launch mode, disconnect in attach modes') but never states when to reach for this tool versus siblings such as tabs or navigate, nor when launch vs connect mode is appropriate. Usage is implied by the action list rather than explicitly guided.

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