build_backend

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

With no annotations, the description carries the full burden. It discloses that the tool stops a running backend first, explains the two modes (incremental vs full) with timing, and highlights the failure condition for incremental builds. It does not cover error handling or side effects beyond stopping the backend, but it provides substantial behavioral context.

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?

The description is a single dense paragraph of three sentences. It front-loads the primary purpose and then provides mode details. While not broken into bullets or sections, it is efficient and every sentence conveys necessary information.

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?

Given the complexity of rebuilding a backend, the description covers all essential aspects: the modes, timing, prerequisites (prior full build), trigger conditions for full mode, and the fact that it stops a running backend. There is no output schema, but for a build tool this is acceptable.

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?

The schema only lists 'mode' with enum values and default 'auto.' The description adds rich meaning: it explains what auto does (incremental when prior full build exists), what full does (complete e2e-build), and when to choose each. This goes far beyond the schema's raw enum values.

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 opens with a specific verb-resource pair: 'Rebuild the transpiled Node backend' and connects it to the downstream effect 'so run_app picks up deployed/edited ABAP.' This clearly distinguishes the tool from sibling tools like run_app or deploy_app, which have different purposes.

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 explicitly explains when to use each mode: auto is incremental when a prior build exists, full is needed for initial builds or framework/port changes. It also mentions when incremental fails (rejects a construct) and suggests fallback actions. It lacks an explicit 'use this instead of X' comparison, but the context is clear.

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