browser_set_headers

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

No annotations are provided, so the description carries the full burden. 'All outgoing requests from the browser' is useful scope information, but it omits whether this applies to the current tab or all tabs, whether existing headers are overwritten or merged, whether a reload is required, and whether the setting persists across navigation. For a mutation tool with zero annotation coverage this is a notable gap.

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 efficient sentence with the action front-loaded and no wasted words. It is appropriately sized, though the brevity is partly a product of missing information rather than disciplined editing.

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 state-mutating browser tool with no annotations and no output schema, the description should clarify scope (current tab vs all tabs), persistence, and merge/overwrite behavior. None of that is present, leaving key operational questions unanswered.

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 description merely restates the single parameter's meaning ('custom HTTP headers'), which the schema already documents as 'Key-value map of HTTP headers'. Baseline 3 applies since the schema does the work and the description adds no format, casing, or override semantics.

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?

Names a specific verb ('Inject') and resource ('custom HTTP headers') with scope stated as 'all outgoing requests from the browser'. An agent can identify what it does immediately, though it does not differentiate itself from the nearest sibling, browser_set_user_agent, which also alters request headers.

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 how this differs from browser_set_user_agent or other request-modifying tools such as browser_block_urls. The agent must infer usage entirely from the name.

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