explain

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

No annotations exist, so the description carries the full burden. It usefully enumerates what the explanation covers (recent results, flakiness, main-branch breakage, selection rationale) and implies it precedes an override rather than performing one, but it never explicitly states the call is read-only/side-effect free or mentions permissions or cost.

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, zero filler: the first states what is explained, the second states when to call it. The guidance is front-loaded where an agent will see it.

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 an output schema present, return shape needn't be described, and the description covers the tool's conceptual role well. The only gap is that it never sketches the relationship between 'main', the current change, and the base/variant parameters, though the schema handles that adequately.

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 100%, so the params (base, test_id, variant, repo_path, include_uncommitted) are already fully documented. The description reinforces the single-test scope ('one test') and the 'current change' context but adds no syntax or mapping detail beyond the schema, so baseline 3 applies.

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 gives a concrete verb and subject: it explains one test's recent results, flakiness/broken-on-main status, and why siftwise would or wouldn't select it. That is more specific than the bare name 'explain' and distinguishes it from the sibling actions (selection, triage verdict) it references. It falls short of a 5 only because it never names select_tests or triage_failure directly as the siblings it complements.

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?

Explicit trigger is given: 'Use it when a selection or a triage verdict surprises you, before overriding it,' which tells the agent both the situation and the ordering relative to an override. No explicit when-not-to-use case is stated, keeping it just under a 5.

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