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

Although readOnlyHint is already annotated, the description adds meaningful behavioral context: it discloses what data the read returns, that it depends on an ID from get_test_run, and that project context is required. This goes well beyond the annotation and helps the agent set correct expectations.

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 compact and front-loaded, beginning with the core purpose and payload contents. Every sentence adds useful information: what it returns, when to use it, where the ID comes from, and the context requirement. There is no wasted text.

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?

With no output schema present, the description compensates by listing the full set of returned data: status code, timing, body, headers, assertions, extracted variables, and script output. It also covers the single parameter's provenance and usage context, making the tool fully invokable without additional lookups.

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 already documents testResultId as a Public Guid of the test result. The description adds valuable semantics by explaining that the id originates from get_test_run's results[].id and not from get_test_results. This is useful extra guidance beyond the schema's basic definition.

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 precise verb and resource: 'Get ONE test case's result inside a run' and enumerates exactly what is returned. It clearly distinguishes this tool from get_test_run and get_test_results by emphasizing singular result vs. run-level identifiers. An agent can immediately understand what this tool does and how it differs from nearby siblings.

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 tells the agent when to use this tool: 'This is the read to make when a run failed and you need to know why.' It also provides the critical ID source, get_test_run's results[].id, and warns against confusing it with get_test_results run ids. This gives clear usage direction and prevents common mistakes.

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