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

The description discloses that no browser is launched, a key behavioral trait. However, it does not mention other potential side effects such as network requests, timeouts, or whether it performs a HEAD vs GET request. With no annotations, this partial disclosure is insufficient for full transparency.

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?

The description is a single, concise sentence that conveys the core functionality and a key differentiator. No unnecessary words or redundant information.

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 is extremely incomplete for a tool with 9 parameters and no output schema. It does not explain what input the tool expects, how to use it, what output it returns (e.g., boolean, status code), or how the extraneous parameters are handled. An agent cannot reliably invoke this tool based on the given information.

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?

The schema has 9 parameters, all optional and with descriptions that are unrelated to the tool's purpose (e.g., 'city', 'feed', 'zone'). The 'url' parameter description says 'normalize or cite' which does not match 'check if can be opened'. The tool description provides no parameter context, leaving the schema misleading and confusing.

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 clearly states the tool checks whether a URL can be opened, and the note 'No browser is launched' differentiates it from browser-based siblings like 'browser-url-ok'. However, it does not explicitly mention the required input parameter (URL), which slightly reduces clarity.

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 implies usage without launching a browser but does not explicitly state when to prefer this tool over alternatives like 'browser-url-ok' or 'fetch-status'. Guidance on when not to use it is absent.

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