Describe the active backend

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

Annotations include readOnlyHint=true, and the description does not contradict this. The description adds the context that backends differ in capability, but does not disclose additional behavioral traits such as output format or performance characteristics. With read-only status already declared, the added value is modest, so a 3 is appropriate.

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, front-loaded with the core function, and the second sentence provides actionable usage advice. No redundancy or fluff.

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 zero-parameter, read-only introspection tool, the description fully covers what the tool does and when to use it. It explains the output at a high level (active backend and supported operations) and does not need an output schema.

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 description carries no parameter burden. Per the rubric, the baseline is 4, and the description meets that baseline by not omitting anything 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 uses the specific verb 'report' with the resource 'active backend' and 'which operations it supports', clearly distinguishing it from the workout-related sibling tools. The title reinforces the same.

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?

Explicitly instructs to 'Check this before planning a sequence of changes', providing clear timing guidance. It also mentions that 'backends differ' which explains why checking is necessary. No alternatives are named, but none are needed given the tool's unique introspection role.

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