check_proxy

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

Annotations already establish readOnlyHint=true, openWorldHint=true, and destructiveHint=false, so the safety profile is clear. The description adds meaningful behavior beyond that: it sends no traffic through the tunnel, returns gateway status, exit IP, and elapsed time, and notes that a 407 can reflect a bad parameter as well as bad credentials. It does not discuss authentication or rate limits, but it is substantially more transparent than the annotations alone.

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 front-loaded and each sentence carries useful information: core action, traffic behavior, return values, error interpretation, and a mobile-specific routing note. There is no obvious filler, though the mobile note could be tighter.

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?

An output schema exists, so the description does not need to explain return values, though it helpfully summarizes them. Safety annotations cover the read-only profile. The major gap is that an 8-parameter tool with zero schema descriptions leaves most filter and session parameters unexplained, which is not complete enough for correct invocation in all cases.

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 8 parameters and 0% description coverage, so the description carries the burden of explaining parameter meaning. It only hints at connection_type="mobile" and that mobile location codes come from list_locations; it never explains isp, ttl, city, filter, region, country, or session_id. This leaves most parameters semantically opaque.

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: opening one connection through the proxy and reporting the result. It also clarifies that no tunnel traffic is sent, which helps distinguish a connectivity check from actual proxied requests. However, it does not explicitly name or contrast the sibling test_proxy_on_site, so it falls short of full sibling differentiation.

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 as a connectivity/credential check and gives a useful troubleshooting hint for 407 responses. It also directs mobile users to list_locations with connection_type="mobile". But it does not explicitly say when to use this instead of test_proxy_on_site, proxy_url, or other siblings, and gives no when-not guidance.

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