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

Beyond the annotations, the description discloses genuinely useful behavior: the skill's own server-side code answers (no model), it cites sources, it refuses rather than guesses out-of-scope asks, and it reports server-clock UTC times. It also points to an "open" link carrying the card, which hints at the return shape. This is meaningful added context on top of readOnlyHint/openWorldHint.

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 definition is padded with promotional, self-referential content ("rated proven on a-to-mind.com from evidence... never from how it describes itself") that does nothing to help an agent invoke the tool. The substantive facts—server-side answering, refusals, UTC times, open link—are buried behind that clutter and the cryptic "(Sky and earth)" parenthetical.

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 two-parameter, read-only tool with full schema coverage and no output schema, the description covers the domain, refusal behavior, determinism, and where the result's card lives. The only omission is any mention of the raw_data output mode, which the schema handles adequately.

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%, so the schema already explains both 'ask' and 'response_type' in detail. The description reinforces 'ask' with example phrasing but never mentions the response_type options (text/raw_data), leaving that entirely to the schema. Baseline 3 is appropriate.

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 opening sentence names the skill and its domain ("country"), and the example asks ("capital of australia", "population of japan") make the resource concrete. It is clear the tool answers country-fact questions, but nothing in the text distinguishes it from the many sibling skill_* tools beyond the domain examples.

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?

Usage is only implied through the example asks; there is no explicit statement of when to prefer this over skill_distance, skill_translate, or other siblings. The line "an ask the skill does not take is refused, not guessed" signals a boundary exists but never tells the agent where that boundary is.

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