get_slowest_testsRanks tests by duration for a recent CI run, tracks duration trends across runs, and flags performance degradation to help target test optimization.
Slowest tests in the latest run with their duration trend across the window; flags performance degradation.
| Name | Required | Description | Default |
|---|---|---|---|
| top_n | No | How many (default 10) | |
| last_n | No | Only consider the most recent N runs (default: all runs) |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds useful behavior (trend across the window, degradation flags) but leaves open what 'flags degradation' means and whether the trend requires multiple runs in the window.
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?
One dense sentence with no filler, and the resource plus scope are front-loaded. Slightly fragmented phrasing ('across the window') but nothing is wasted.
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 two-optional-parameter read tool with annotations and no output schema, the definition is broadly sufficient to call it. It does not clarify ordering of results, what constitutes a degradation flag, or the minimum data needed for a trend, which are the remaining gaps.
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%, with both top_n and last_n fully documented including defaults and bounds, so the schema carries parameters. The description only weakly reinforces them via 'across the window', adding little beyond the schema — 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?
States a clear resource (slowest tests) with scope modifiers — latest run plus the duration trend across the window — and adds degradation flagging. It is distinguishable from siblings such as get_pass_rate_trend and find_flaky_tests by resource, though it doesn't name an alternative.
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?
Usage is only implied: an agent can infer this is for performance analysis. There is no explicit when-to-use or when-not, and no disambiguation from detect_regressions, which also deals with performance problems — a real ambiguity given both mention degradation/regression behavior.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.