Explain Growth

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

No annotations are provided, so the description carries the full transparency burden. It discloses that the tool operates on already loaded builds, performs an analytical rather than mutating task, and returns a structured set of findings and summary. It does not explicitly discuss side effects or prerequisites beyond loaded builds, but the verbs and return list make the behavior clear.

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 purpose-dense sentences contain every necessary element: the scope, the analytic target, and the returned output. There is no filler, no repetition of schema details, and the core intent is front-loaded.

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 no output schema, the description adequately names the main return categories and the precondition of two loaded builds. It does not explain ranking methodology or explicitly route around overlapping siblings, but parameter mechanics are fully covered by the schema, making the overall description sufficient.

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?

All three parameters have complete schema descriptions, including the omit-to-list behavior for build IDs. The tool description adds context about the overall analysis but no parameter-level meaning beyond the schema, so the baseline score of 3 is appropriate.

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 analytical verb ('Identify') and resource ('routes and chunks') plus the exact condition ('bundle size growth between two loaded builds'). The mention of severity-ranked route findings, top growing chunks, and a regression summary distinguishes it from general comparison siblings like compare_builds.

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?

The description clearly implies a two-build comparison scenario, but it never explicitly states when to choose explain_growth over siblings such as compare_builds or explain_shared_chunks. There are no exclusions or alternative routing cues beyond what the name and scope suggest.

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