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

Adds real context beyond the annotations: destructiveHint=false is reinforced by stating the browser keeps running, so the agent knows state is preserved on the remote side. It doesn't cover what happens to the session ID's validity afterward or whether reconnect is possible, so not a 5.

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 short sentences, front-loaded with the action, second sentence carrying the crucial disambiguation. Zero waste.

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 one-param, non-destructive teardown tool with full schema coverage and annotations, nothing material is missing — the lifecycle relationship to close_browser is the one thing an agent needs and it's stated.

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 description coverage is 100% and the single sessionId param is already documented in the schema; the description adds no format, provenance, or reuse semantics beyond it. Baseline 3 applies.

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?

Specific verb ('disconnect') plus resource (

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?

States the key selection rule: use close_browser if you actually want to stop the browser, implying this tool is for releasing the control session while leaving the browser alive. No explicit 'do not use when' beyond that, so not quite a 5.

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