dnr_matched_rules

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

With no annotations provided, the description carries the full burden. It adds a key behavioral detail by requiring the declarativeNetRequestFeedback permission, and clarifies the meaning of 'matched rules' as 'which rules fired'. It does not describe the return format or error behavior, but the permission disclosure goes beyond the bare minimum.

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 two concise sentences, front-loaded with the primary action and immediately clarifying what the tool returns. No wasted words, and the permission requirement is stated separate from the core purpose.

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 simple read tool with one optional parameter and no output schema, the description covers the core behavior and notes the required permission. It does not explicitly state the return shape (e.g., a list of matches) but implies it with '(which rules fired)'. Overall, it provides sufficient context for an agent to select and invoke 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?

Schema description coverage is 100% for the single optional parameter tabId, with a clear description in the schema. The tool description itself does not mention tabId, so it adds no additional semantic value beyond the schema. Baseline of 3 applies since the schema fully documents the parameter.

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 tool gets declarativeNetRequest matched rules, and clarifies the meaning by appending '(which rules fired)'. This specific verb+resource combination distinguishes it from sibling tools like dnr_rules (which likely manages rules) and network_requests (which likely fetches network requests).

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: call this tool when you need to see which declarativeNetRequest rules matched. However, it does not explicitly state when not to use it or mention alternatives such as dnr_rules or network_requests. The permission requirement is noted but without guidance on prerequisite setup.

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