Lists the largest retained-heap dominators from a MAT report and drills into child objects by parent objectId to locate memory hogs.
Dominator tree: list biggest retained-heap dominators, drill down by passing parent objectId. / 支配树：列出 retained 最大的支配者，传 parent=objectId 可下钻。
| Name | Required | Description | Default |
|---|---|---|---|
| top | No | ||
| parent | No | ROOT | |
| report_id | Yes |
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations exist, so the description carries the full burden. It does disclose implicit ordering ('biggest retained-heap dominators') and the hierarchical drill-down model, but says nothing about whether results are truncated, paging behavior, or cost of the traversal.
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?
A single compact sentence pair with the core purpose front-loaded, plus a bilingual mirror that adds no new information cost. No filler text, though the duplicated Chinese rendering doubles length for no semantic gain.
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?
Output schema exists so return values needn't be described, and the drill-down mechanic is covered. But for a 3-parameter tool with zero schema descriptors and no annotations, leaving report_id and top unexplained leaves an agent guessing about inputs.
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 0%, and the description explains only 'parent' (pass an objectId to drill down). The required 'report_id' and the 'top' limit (default 20) are never addressed, and the schema's default value 'ROOT' for parent is not mentioned either.
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: 'Dominator tree: list biggest retained-heap dominators' with drill-down by parent. An agent can distinguish this from mat_histogram or mat_leak_suspects by the 'dominator tree' framing, though no sibling is named explicitly.
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?
Gives concrete mechanics for one workflow ('drill down by passing parent=objectId') but never says when to choose this over mat_histogram or mat_leak_suspects, nor any prerequisites such as needing an open heapdump report first.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.