buildx_list

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

Annotations already indicate readOnlyHint=true and destructiveHint=false, but the description adds valuable behavioral context: it raises RuntimeError on CLI failure, and drops the last partial record if stdout is truncated by MAX_CLI_OUTPUT_BYTES. This goes beyond the structured metadata and sets expectations for edge cases.

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 compact and well-structured: a one-sentence summary, then usage guidance, error behavior, and return format. No wasted words; every sentence serves a purpose and the most important information 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 simple list tool with no parameters and no output schema, this description is complete. It covers the purpose, alternatives, error behavior, truncation handling, and return format. Nothing important is missing.

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 input schema has zero parameters, so the baseline is 4. The description does not need to add parameter semantics, but it does explain the return format (list of dicts parsed from '--format {{json .}}'), which is helpful for understanding the output.

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 starts with 'List builder instances,' which is a specific verb+resource statement. It further clarifies the scope with 'Machine-parsed view of every builder' and distinguishes itself from siblings by referencing buildx_inspect for human-readable detail and buildx_use for switching the default.

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?

Provides explicit guidance on when to use this tool versus alternatives: 'use `buildx_inspect` for one builder's human-readable detail and `buildx_use` to switch the default.' This clearly directs the agent to the appropriate tool for different needs.

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