cross_branch_ab_report

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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds the Pro-tier entitlement requirement, which is genuinely useful context, but says nothing about how the ranking is computed, whether results are cached, or what the branch-exclusion behavior does to aggregates.

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, with the core action front-loaded and the entitlement caveat immediately after. No filler, though the second line reads as a fragment rather than structured guidance.

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?

There is no output schema, and the description says nothing about what the report returns — a ranked list, per-branch sample sizes, significance measures. For an analytics tool whose whole value is the shape of the report, that leaves a meaningful gap, even though annotations and a fully documented schema cover the rest.

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 both design_id and min_outcomes_per_branch (including its default of 3) are already fully documented in the schema. The description adds no meaning beyond that, so the baseline of 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?

States a specific verb and resource: rank semantic features by measured outcome impact across branches. An agent knows what the tool produces, but the description never distinguishes it from the near-identical siblings cross_feature_ab_report and cross_preset_ab_report, so sibling disambiguation is left to the name alone.

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?

'Needs Kiln Pro' is a real prerequisite that tells the agent about a gating condition, which is more than nothing. But there is no guidance on when to pick this over compare_branches or the other two ab_report variants, and no exclusion criteria are stated.

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