list_countriesList Proxy302-targetable countries and return IDs for use in other proxy tools. Apply an optional name substring filter to find a specific country quickly.
List countries Proxy302 can target. Optional name filter (substring). Returns ids usable in other tools. Read-only.
| Name | Required | Description | Default |
|---|---|---|---|
| name | No | Filter, e.g. "ger" |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and openWorldHint=false, so "Read-only" in the description merely repeats structured data. What does add value is the downstream note that returned ids feed other tools. Nothing is said about result size, ordering, or behavior when the filter matches nothing.
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 short front-loaded sentences with the scope stated first and the filter and return semantics after. The trailing "Read-only" sentence is redundant with the annotations and is the one piece that doesn't earn 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 one-optional-param read tool with no output schema, the description covers purpose, filtering, and the shape of returned values (ids usable downstream). Only the relationship to list_regions and the no-match/ordering behavior remain unstated.
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 gives an example ("ger"), so the baseline is 3. The description's "(substring)" does clarify match semantics beyond the schema, but that is a marginal gain.
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?
States a concrete verb+resource ("List countries Proxy302 can target") and adds the key qualifier that results are usable as ids in other tools. It does not, however, distinguish itself from the sibling list_regions, which an agent could plausibly confuse with country listing.
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 phrase "Returns ids usable in other tools" implies a discovery-then-use workflow, which is useful context. But there is no explicit when-to-use guidance and no statement of when to prefer list_regions or how the two differ.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.