replay_flow

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

With no annotations, the description carries the full burden, and it does well: it discloses that the request goes through mitmproxy with curl_cffi/browser impersonation, that this creates a new flow in mitmweb, and that existing flows are never modified. It could add what happens on timeout or failure, but the key behavioral safety profile is clear.

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?

Three short paragraphs each earn their place: purpose, side-effect/behavior, and parameter semantics. The most important scoping statement ('existing flows are never modified') is placed early, and the example makes the headers semantics concrete without bloat.

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?

The description covers what the tool does, how the request is transported, the side effect in the UI, and how the main optional parameters behave. Given that an output schema exists, return values are not required; minor gaps around body_max/timeout keep this from a 5.

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?

Despite 0% schema description coverage, the description explains the important parameters: header override/add semantics with an example, body replacement with JSON serialization for dicts/lists, and accepted impersonate values. It leaves timeout and body_max to their names/defaults, but the core parameters are meaningfully documented.

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?

States the precise action 'Replay a request' and immediately adds the optional modifications (method, headers, body), so an agent knows exactly what the tool does. The 'like Burp Repeater' analogy and the note that it creates a new flow while existing flows are never modified clearly separate it from the inspection/status/diff sibling tools.

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 gives clear context: it is for replaying a captured request, optionally rewriting it, and observing the result as a new flow in mitmweb. It does not explicitly compare itself to sibling tools like inspect_flow or generate_code, so it stops 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.