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

Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=false), so the description's job is to add context, and it does supply one useful cue: this is a gate check preceding joining/wishing/ordering. Beyond that it discloses nothing about what a closed or open result means, what the response looks like, or what the caller should do next, and there is no output schema to fill that gap.

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 short sentences, front-loaded with the purpose and followed by the trigger list; nothing is padded. The closing "or check on anything" is slightly loose and blurs the boundary of the trigger list, but the overall structure is efficient.

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?

The tool is simple (no params, no nested objects) and the description covers purpose and triggers adequately. However, with no output schema and only a readOnly annotation, an agent still cannot tell whether the result is a boolean, a status string, or includes hours/detail, nor what to do when the answer is "closed" — a meaningful gap for a gate-check tool.

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 and the schema cannot be supplemented by description text. The description correctly implies a parameterless, no-input check by giving no argument syntax.

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 opens with a specific verb-plus-resource pair: "Check whether Unfactory is open," which tells an agent exactly what the tool answers. It narrows the concept with "open for wishes and orders," though it never defines what "open" means operationally. There are no sibling tools, so no differentiation is needed.

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?

It gives concrete call triggers: the person asks to join, make three wishes, order something, or check on anything. That is a clear use-this-when list rather than an implied one. It stops short of stating any exclusions or prerequisites (e.g., whether it should always be called before ordering), but with no siblings those are largely unnecessary.

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