Set runtime policies for a browser automation session, including read-only mode, JavaScript evaluation, and allowed or blocked domains.
Set runtime policy for one session.
| Name | Required | Description | Default |
|---|---|---|---|
| read_only | No | ||
| session_id | Yes | ||
| allow_evaluate | No | ||
| allowed_domains | No | ||
| blocked_domains | No |
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
v0.5.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations, so the description carries the full behavioral burden for a mutation tool. 'Runtime' weakly hints the policy is session-scoped and non-persistent, but nothing is said about required permissions, whether null values mean 'leave unchanged' (all four policy params default to null), or whether the policy survives the session.
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 short sentence is not conciseness here — it is under-specification. The one clause it contains is front-loaded and wastes no words, but it omits essentially all of the information an agent needs.
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 5-parameter mutation tool with no annotations and 0% schema coverage, this is wholly inadequate. The presence of an output schema excuses only return-value documentation; nothing else the agent needs is present.
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 0% across 5 parameters, so the description must compensate and it does not. None of read_only, allow_evaluate, allowed_domains, or blocked_domains is mentioned, and the nullable-with-null-default semantics that govern every optional param are unexplained.
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 plausible verb+resource combination ('Set runtime policy for one session'), but 'runtime policy' is left undefined — the schema's actual policy surface (read_only, allow_evaluate, allowed_domains, blocked_domains) is never surfaced. It also fails to distinguish itself from the sibling session_get_policy, which is the obvious read counterpart.
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?
No when-to-use guidance, no prerequisites, and no mention of the sibling session_get_policy for inspecting current policy. The agent is left to infer that this is the write counterpart to session_get_policy.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.