open_test_run

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

Annotations already declare destructiveHint=true, readOnlyHint=false, openWorldHint=true, and idempotentHint=false. The description adds that reopening enables continued creation and updating of test results, but does not explain what side effects occur, what permissions are needed, or what happens to existing data. With annotations covering the safety profile, this is a modest addition.

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?

Three sentences are front-loaded with the core action, but the first sentence 'Open a test run.' is redundant with the tool name and the second sentence repeats the same verb. Some words could be trimmed without losing meaning.

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 mutation tool with annotations but no output schema and one nested parameter, the description covers the basic purpose and a key effect. However, it omits prerequisites, permission requirements, and what specifically happens when a run is reopened (e.g., whether it alters existing results), leaving gaps that annotations alone do not fill.

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 0% at the top level, though the nested testRunId field has its own description. The description says 'using its unique identifier', which maps to that parameter but adds little beyond what the schema already states. With only one parameter and partial schema coverage, the description does not fully compensate.

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 states a specific verb (open) and resource (test run), and adds the state qualifier 'previously closed', which distinguishes it from creating a new test run. It does not explicitly differentiate from close_test_run or restore_test_run, but the purpose is clear.

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 implicitly says when to use it: to continue creating and updating test results on a closed run. However, it never names alternatives (e.g., close_test_run, restore_test_run) or when not to use it, leaving the agent to infer context from the name.

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