Set Browser Headers

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

Annotations already declare destructiveHint, idempotentHint, and openWorldHint. The description adds valuable context about success behavior ('echo header values for MCP callbacks') and the clearing mechanism ('empty object clears them'), which goes beyond annotations without contradicting them.

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?

The description is compact and front-loaded, with two sentences that state purpose, scope, and key behaviors. Every word earns its place; there is no extraneous information.

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?

Given the single parameter with a rich schema, available output schema, and annotations indicating destructive/idempotent behavior, the description sufficiently covers the behavioral essentials. It explains how to clear headers and what to expect on success, making it complete for this complexity level.

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?

The schema provides 100% coverage for the 'headers' parameter, including a description that matches the tool's mention of 'empty object clears'. The tool description adds no new parameter-specific meaning beyond what the schema already provides, so baseline 3 is appropriate.

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 clearly states the action ('Replace'), the resource ('extra HTTP request headers'), and the scope ('for the current tab'). This distinguishes it from sibling tools like browser_user_agent_set or browser_cookies_set, which handle different request aspects.

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?

The description implies usage for setting headers on the current tab, but it does not explicitly mention alternatives or exclusions. There is no when-not-to-use guidance relative to sibling tools, so context is clear but not thoroughly differentiated.

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