browser_tool_schemaFetches a browser tool's input schema and description so AI agents can invoke it with the correct parameters.
Full description and JSON input schema of a tool from browser_list_tools, e.g. "webmcp.search" or "devtools.performance_start_trace".
| Name | Required | Description | Default |
|---|---|---|---|
| name | Yes | Qualified tool name from browser_list_tools. | |
| sessionId | Yes | Session id returned by browser_start. |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description does not add anything beyond that, such as behavior on an invalid or unknown tool name, so with annotations doing the work a 3 is appropriate.
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 front-loaded sentence with zero filler that both states the result and illustrates the name format. Nothing is padded or redundant.
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 helpfully discloses what is returned (full description plus JSON input schema) and where names come from. It omits error behavior for an unknown tool name, which is a minor 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%, so the baseline is 3, but the description adds format-level meaning by giving concrete qualified-name examples ('webmcp.search', 'devtools.performance_start_trace') that go beyond the schema's 'Qualified tool name from browser_list_tools'.
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 states a specific verb+resource: it returns the full description and JSON input schema of a named tool. It also ties itself to the sibling browser_list_tools as the source of valid names, though it does not distinguish itself from other schema/introspection siblings explicitly.
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 implies a clear two-step workflow by stating the name must come from browser_list_tools, which gives the agent a prerequisite. It does not state when-not to use it or name a competing alternative, so it falls short of a 5.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.