Report which backend is available

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

With no annotations provided, the description carries the full burden. It transparently explains what the tool reports and adds interpretive value ('telling a downgrade apart from a deliberate offline run'), which goes beyond the title. It does not describe side effects or authorization needs, but for a read-only status check with zero parameters, this is adequate and not misleading.

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 description is two concise sentences with no superfluous content. The first sentence states the core function; the second adds practical value. It is front-loaded and every word earns 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 simple zero-parameter tool with an output schema, the description is complete. It explains what the tool does and why it's useful, and the existence of an output schema means the return values need not be described in the text. No gaps are apparent.

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 has zero parameters, so the baseline is 4. The description does not need to explain parameters since there are none. The schema coverage is 100% (empty schema), and no parameter information is required.

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 clearly states the tool's function: it reports whether a language model is configured or if the server will use the offline rule parser. This specific verb+resource (says/reports backend status) distinguishes it from siblings like create_diagram and validate_diagram, which perform different actions.

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 provides a clear usage context: 'Useful for telling a downgrade apart from a deliberate offline run.' This implies when to use the tool (when you need to distinguish between a downgrade and an intentional offline mode), but it does not explicitly mention when not to use it or compare it to alternatives. Still, the guidance is sufficient given the simple nature of the tool.

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