browser_block_urls

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

No annotations are provided, so the description carries the full behavioral burden, and it omits key traits: whether blocked patterns persist across navigations or tabs, whether they can be unblocked, how glob matching works, and what happens to already-loaded requests. It only conveys the intent of the blocking, not its mechanics or side effects.

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 no filler; the purpose and examples come before the rationale. It is appropriately sized for a one-parameter tool, though it leaves behavior unexplained.

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-parameter tool with no annotations or output schema, the description covers what the tool does and the pattern syntax needed to call it correctly. It is incomplete on lifecycle/scope questions (persistence, per-tab vs. global) that matter for a browser-mutating operation.

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% ("Wildcard URL patterns to block"), so the schema already documents the single parameter. The inline examples in the description ("*.png, *analytics*, *ads*") usefully clarify the wildcard format, but add only marginal value beyond the schema.

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 action (block) on a specific resource (URL patterns) and even illustrates the pattern syntax with examples like *.png and *analytics*. It does not, however, distinguish itself from the sibling browser_block_resources, which is the most likely tool an agent could confuse it with.

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?

Usage is implied by the stated goal ("to speed up page loading"), which tells the agent roughly when this tool is relevant. There is no explicit guidance on when to prefer this over browser_block_resources or browser_set_headers, and no scoping conditions are given.

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