Set Blocked URLs

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

The description adds valuable behavioral context beyond the annotations: it is a replace operation, successful results echo the input patterns, and an empty list clears the blocked URLs. These details help the agent understand the operational semantics, while annotations already signal destructiveness and idempotency.

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 a single front-loaded sentence that states the action, scope, and key behavioral details without any wasted words. It is concise and well-structured.

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 tool's simplicity (one parameter), detailed schema descriptions, and the presence of an output schema, the description covers all essential aspects: purpose, scope, clearing behavior, and result echo. There is no apparent gap that would cause an agent to misuse the tool.

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 input schema already fully describes the single 'urls' parameter, including wildcards and empty-list clearing. The description does not add new parameter-level information; it only reinforces the empty-list behavior, which is already present in the schema. With 100% schema coverage, the baseline of 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') and the specific resource ('URL patterns blocked for the current tab'). This distinguishes it from sibling tools like network_listen_start/stop or browser_cookies_set, which have different purposes. The scope is precise and unambiguous.

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 provides clear context: it operates on the current tab and indicates the empty-list clearing behavior. However, it does not explicitly mention alternatives or exclusions, though these are implied by the replace action and the tool's specific purpose.

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