check_proxy

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

Annotations already declare readOnlyHint=true, and the description reinforces this with 'Changes nothing' while adding useful behavioral context: it makes a real request, can take up to about ten seconds, and reports connectivity, IP, country, and latency. This exceeds the annotations' safety-only coverage without contradicting them.

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?

Three compact sentences with no filler: the first states the action and expected outputs, the second adds side-effect and timing constraints, and the third routes to the sibling tool for multi-profile use. Every sentence earns its place and the key info is front-loaded.

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 one-parameter, low-complexity tool with no output schema, the description covers everything an agent needs: what it does, what it returns, that it is non-destructive, how long it may take, and when to choose the sibling tool. No critical gap remains.

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%, and the schema already documents that 'profile' is the exact name returned by list_profiles. The description adds little beyond specifying the single-profile scope, so the baseline of 3 is appropriate; the schema carries the parameter-semantics burden.

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 uses a specific verb ('Test'), identifies the resource ('one profile's proxy'), and enumerates the delivered information: whether it answers, exit IP and country, and latency. It also clearly distinguishes itself from the sibling check_proxies, so an agent can immediately tell which tool is which.

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 explicitly tells the agent when to use the alternative tool: 'For several profiles use check_proxies instead.' It also clarifies the single-profile scope and the approximate time cost, giving clear decision criteria without requiring schema inspection.

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