Compare Builds

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

With no annotations, the description carries the full burden for behavioral disclosure, but it only describes the happy-path comparison. It fails to mention that omitting both build IDs lists loaded builds instead of comparing, and it says nothing about error behavior or reliance on load_build_stats. This is a notable transparency gap for a tool with a dual mode.

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, front-loaded sentence states the action, subject, and result with no filler. It is appropriately concise for the tool's complexity.

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 only vaguely indicates the output ('which routes and chunks grew or shrank the most'). It omits the fallback behavior of listing loaded builds when IDs are omitted, which is important for correct invocation. Still, the primary use case is clear enough for an agent to attempt a correct call.

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 the baseline is 3. The description adds broad context about comparing routes and chunks but does not clarify parameter meaning beyond the schema, such as how limit applies or which build IDs to use.

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 uses a specific verb ('Compare') with a clear resource ('two loaded Next.js builds') and a concrete outcome ('show which routes and chunks grew or shrank the most'). This clearly differentiates it from siblings like get_largest_routes, which analyze a single build, and load_build_stats, which loads 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 when to use this tool: when the user wants to compare two builds that have already been loaded. However, it does not explicitly mention alternatives or exclusion conditions, such as using get_largest_routes for a single build or explain_growth for understanding why growth occurred.

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