explain_vrt_failure

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

There are no annotations, so the description must fully disclose behavior. It indicates the tool generates hypotheses and next actions, but it does not state if it is read-only, requires authentication, has rate limits, or modifies any state. The description provides minimal behavioral insight beyond the broad output nature.

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, well-structured sentence that is highly concise and front-loaded with the key action. It avoids fluff and is easy to parse, though it could benefit from a brief breakdown of parameters or output.

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 the presence of 4 parameters, no annotations, no output schema, and many sibling tools, the description is incomplete. It does not explain the role of each parameter, the expected output format, or how this tool integrates into the VRT workflow. The agent is left with an ambiguous understanding.

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 schema has 4 parameters with zero descriptions (0% coverage), and the tool description mentions none of them. The agent must infer that 'project', 'environment', 'scenarioLabel', and 'viewport' likely identify a specific VRT failure, but no semantic help is given. This is a significant gap.

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 does 'Structured VRT failure analysis with hypotheses and next actions,' which effectively communicates its purpose and distinguishes it from sibling tools like 'get_run_failures' (retrieval) and 'compare_runs' (comparison). The use of 'structured' and 'hypotheses/next actions' adds valuable specificity.

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?

No guidance is provided on when to use this tool versus sibling alternatives. With many related tools (e.g., 'get_run_failures', 'get_diff_stats', 'check_setup_health'), the agent lacks context about prerequisites or typical workflow, such as whether to call this after 'get_run_failures' or 'get_scenario_details'.

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