Open a page in the browser

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

Annotations only declare openWorldHint=true and destructiveHint=false; the description adds real behavioral context that annotations do not cover — the hard host allowlist, the use of the default browser, and the failure mode for disallowed hosts. It still omits whether the page contents are returned or what the response looks like, but that is a modest gap for this simple tool.

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, no filler, and the positive capability is front-loaded ahead of the refusal constraint. Every clause earns its place.

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?

For a single-parameter tool with no output schema and only two annotations, the description supplies the critical constraints (protocol, allowed hosts, failure on other hosts) an agent needs to invoke it correctly. It could add a word on return behavior, but nothing essential is missing.

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 0%, so the description must carry the parameter burden. It does partially compensate by implying the URL must be https and its host must be in the allowlist, which is meaningful constraint information beyond a bare 'string'. It still gives no full URL syntax or example, so the gap is only partly closed.

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 names a specific verb and resource (open a page in the default browser) and pins the exact scope with an explicit host allowlist. That scope statement alone distinguishes it from every sibling in this server, none of which open external pages.

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?

It effectively states when the tool works (github.com, npmjs.com, pypi.org, crates.io) and when it will not ('Other hosts are refused'), which is a clear usage boundary. It does not name alternative tools to use instead, so it stops short of full when/when-not/alternative guidance.

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