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

With no annotations provided, the description carries the full burden of disclosure, but it only says no browser is launched. It does not state whether the tool makes a network request, follows redirects, mutates anything, or how 'opened' is determined, leaving important behavioral facts unstated.

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 short sentences contain the core purpose and the key caveat with no filler. The main action is front-loaded and the browser-related caveat is necessary given the playwright-url-ok name.

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?

Despite concise wording, the definition is incomplete for a tool with 9 optional parameters and no output schema or annotations. It never explains what the tool returns, what qualifies as 'can be opened,' or how the unrelated-looking parameters like city, zone, and query fit into the call.

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%, so the baseline applies; each parameter is already documented in the schema. The description itself adds no parameter-level detail, so it neither harms nor improves on the structured definitions.

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 states a specific action and resource: 'Check whether a URL can be opened.' The added 'No browser is launched' hints at a distinction from the sibling browser-url-ok, but it does not explicitly define what 'opened' means (HTTP reachability vs. link validity), leaving some ambiguity.

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 note that no browser is launched implies this is the no-browser variant compared to browser-url-ok, so there is some implied usage context. However, it does not explicitly say when to prefer this tool over siblings such as fetch-status, normalize-url, or browser-url-ok, leaving the selection largely to inference.

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