Open a URL

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

Adds useful context beyond annotations — namely that it waits for load, returns the final URL and title (important after redirects), and that prior snapshot refs are invalidated ('Refs from earlier snapshots stop working'). That last point is a real consequence an agent needs. However, it doesn't mention that this is a state-changing navigation (readOnlyHint=false) that could trigger page-level side effects, or any auth/rate considerations. Reasonable but not rich.

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 sentences, front-loaded with the core action and scope, then the return value, then the caveat about snapshot refs. Every sentence earns its place with no 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?

Covers the key facts an agent needs: it's an http(s) navigation in the recorded tab, it waits for load, what it returns, and that snapshot refs are invalidated. No output schema exists, and the description compensates by naming the return values. Could be slightly stronger on when navigation alone is sufficient versus when a wait_for is needed, but it's solid.

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 coverage is 100% — both url and timeoutMs are fully described in the schema, including maxLength, min/max bounds, and default. The description adds nothing about parameters beyond what the schema provides, which is the baseline 3 when the schema does the heavy lifting.

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 a specific verb ('Open') and resource ('http(s) URL'), plus the critical scoping detail that it happens 'in the tab the user handed to Recordful'. This distinguishes it clearly from siblings like click, snapshot, or get_status, which operate on an already-loaded page.

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?

Positions the tool implicitly as the entry point to a browsing session — you navigate before you snapshot, click, or type. It doesn't explicitly say 'use this first' or name alternatives for loading content, but the workflow context is clear enough for an agent to place it correctly among the recording/browsing siblings.

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