frames_list

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

With no annotations provided, the description carries the full burden. It discloses the scope (top document plus every reachable iframe) and the intended use case, which conveys it is a read-only listing operation. It doesn't mention potential edge cases (e.g., empty results) but the purpose is clear and no contradictions exist.

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 sentences with no filler. The primary function is front-loaded, and the usage guidance is packed into the second sentence. Every word earns its place.

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 listing tool, the description fully covers what it does, when to use it, and what to do with the output. There is no output schema, but the description explicitly mentions the returned fields (id and URL), so an agent has everything needed to call it correctly.

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 description covers the single parameter (tabId, defaults to active tab) at 100% coverage. The description adds no new meaning about the parameter beyond what the schema already provides, so the baseline score of 3 applies.

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 verb 'List', the resource 'tab's frames', and specifies what is returned (each frame's id and URL). It distinguishes from sibling tools by focusing specifically on frames rather than general content or navigation.

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?

It provides an explicit when-to-use scenario ('when a selector that should match does not') and explains the next step (pass frameId or allFrames:true). This gives an agent clear guidance on both when to invoke and how to apply the result.

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