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

The description discloses the key trait that no browser is launched, which is useful. However, with no annotations, it does not explain what the tool actually does instead (e.g., HTTP request), what it returns, or whether external network access is needed. This leaves the agent guessing about the underlying behavior.

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 deliver the core purpose and the key differentiator with no waste. The main action is front-loaded, making the description easy to scan and act on.

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 does not state the return type or what 'ok' means, and there is no output schema to fill the gap. It also fails to clarify which of the nine loosely-related parameters are actually used, leaving an agent uncertain about how to call the tool correctly. This is incomplete given the large parameter set and the absence of structured behavioral metadata.

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%, so all nine parameters already have individual descriptions, making 3 the baseline. The tool description adds no guidance on which parameters matter most or how they relate to the URL check, so it does not improve on the schema.

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 clear action and target: 'Check whether a URL can be opened.' The additional clause 'No browser is launched' differentiates it from the sibling browser-url-ok, so an agent can tell which tool to pick.

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 'No browser is launched' hint implies a lightweight alternative to browser-based checks, but it never explicitly says when to use this tool versus alternatives like browser-url-ok or web-fetch. No exclusions or conditions are given, so usage context is only implied.

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