List flaky tests

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is covered. The description adds a non-obvious behavioral trait: 'Expensive - one engine pass over the project's recent runs', which is valuable cost/performance context beyond the annotations. It also mentions the output field timeLostMs, but that's partially covered by the output schema. No contradiction.

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 zero fluff. The primary purpose is front-loaded, followed by a cost warning and an alternative tool reference. Every sentence earns its place.

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 tool with 6 parameters, an output schema, and rich annotations, the description is complete. It covers purpose, cost, and routing to the right sibling. Pagination, filtering, and sorting are documented in the schema; return format is in the output schema. Nothing an agent needs to call it correctly is missing.

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 coverage is 100%, so all parameters are already documented with descriptions. The description adds minimal parameter-specific meaning—it mentions timeLostMs as an output field, but doesn't clarify any parameter semantics beyond the schema. Baseline 3 is appropriate since the schema carries the load.

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 ('list') and resource ('the project's flaky and broken tests'), and clarifies it is ranked with time cost. It explicitly distinguishes from the sibling squally-get-test-status by saying 'For a single test use squally-get-test-status instead', so an agent can tell them apart without opening schemas.

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?

It gives explicit context: this is for listing flaky/broken tests across a project, and warns it is expensive. It names the alternative for single-test queries and implies when not to use it. Clear exclusions and context are provided.

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