list_frames

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

The annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and closed-world, so the safety profile is covered. The description adds that this is a diagnostic navigation, but says nothing about failure/timeout behavior or what 'reachable: false' means in practice, leaving room for more behavioral context.

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?

Two tight sentences with the 'Diagnostic:' qualifier front-loaded, then the purpose and the debugging use case. Zero filler.

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?

With no output schema, the description usefully enumerates the returned frame fields, and the 2 parameters are fully documented in the schema. Only minor gaps remain — no mention of how navigation failures are surfaced or the cost/latency of loading a page.

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%, with the url allowlist/constraint and the wait_for enum documented in the schema itself. The description restates the URL concept but adds no syntax or format detail beyond the schema, so the baseline 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 names a specific verb+resource ('navigate to a URL and return its frame tree') and enumerates the returned fields (frame_path, url, name, same_origin, reachable), which distinguishes it from the extract_* siblings that consume the tree rather than report it. It stops short of explicitly naming a sibling, so it is clear but not fully differentiated.

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 gives a clear use context — 'debugging cross-origin iframe boundaries before extraction' — which implicitly positions it ahead of the extraction tools. There is no explicit when-not guidance or named alternative, so it falls just short of a 5.

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