List country marketplace URLs

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

No annotations exist, so the description carries the burden; it discloses that the data is static (no side effects, no live API ownership lookup) and that no credentials are needed. It stops short of describing the exact return shape (a flat key-to-URL map?), which is the only remaining gap for a zero-param 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 sentences plus an example list, zero filler, with the core mapping front-loaded and the sibling routing rule second. The parenthetical examples earn their place by clarifying what a 'country key' looks like.

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 trivial zero-param static lookup with no output schema, the description covers purpose, safety, and alternative. A brief note on the response shape (e.g. map of key to URL) would fully close it, but nothing prevents a correct call.

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 tool takes zero parameters, so the baseline is 4. The description's mention of 'country keys' is contextual framing rather than parameter documentation, and nothing is missing.

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 specific mapping (static country keys to marketplace base URLs) with concrete example keys, and explicitly names the sibling get_owned_marketplaces as the different thing. An agent can distinguish it from the many get_* tools without opening a schema.

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?

Gives an explicit routing rule: use this for static country keys, use get_owned_marketplaces for API-owned marketplaces. It also notes no credentials are required, so the agent knows no auth flow precedes the call.

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