get_runner_info

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

The description discloses that the tool reads an environment variable and returns configuration data, implying a read-only operation with no side effects. Without annotations, it provides sufficient behavioral context.

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 a single paragraph that covers all necessary points: purpose, usage guidance, and return format. It is clear and informative, though slightly verbose.

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?

Given no parameters and no output schema, the description provides a complete overview including return shape and context. It could mention error cases (e.g., missing env variable) but is otherwise thorough.

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 input schema has no parameters, so schema description coverage is 100%. The description does not add parameter meaning beyond the schema, which is expected. Baseline score of 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 description clearly states the tool returns the active runner from the QA_RUNNER environment variable along with the list of all built-in runners. It distinguishes itself from sibling tools by focusing on runner configuration info.

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 explicitly recommends calling this tool first in each session and explains how the returned information is used to decide which test framework to generate, whether to use headed browser, and to verify environment setup.

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