builds_start

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It does reveal a key behavior: 'The branch/tag name is resolved to a Git reference ID via the API.' This adds useful context. However, it omits other behavioral aspects such as side effects, error conditions, or permission requirements, which are important for a build-triggering mutation tool.

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 relatively concise at two sentences. The first sentence states the core purpose, and the second provides a crucial alternative. There is minimal waste, though the leading '[XcodeCloud/Builds]' prefix and extra whitespace add minor noise. Overall, it is efficient and front-loaded enough for a high score.

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?

The tool has an output schema, so return values need no explanation. However, with no annotations and 0% schema coverage, the description needs to provide more context for a mutation tool. It gives the main flow (branch/tag resolution) and a sibling alternative, but leaves parameters like pull_request_number and workflow_id unclear, and lacks details on failure handling or prerequisites. It is adequate for basic use but not fully complete.

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 has 0% description coverage for parameters, leaving the description to compensate. It explains the role of source_branch_or_tag ('branch or tag name') and contrasts it with direct ID usage, but it does not clarify workflow_id (required) or pull_request_number at all. This is insufficient given the complete lack of schema descriptions, so the tool fails to help the agent understand all parameters.

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 clearly states the tool's function: 'Start a new build using a branch or tag name.' It uses a specific verb ('Start') and resource ('new build'), and explicitly distinguishes it from the sibling tool builds_start_by_ref_id by noting the alternative for direct ID usage. This makes the purpose unambiguous and well-differentiated.

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 provides explicit usage guidance by stating 'For direct ID usage without resolution, use builds_start_by_ref_id.' This clearly indicates when to use this tool (when you have a branch/tag name) versus the alternative. However, it does not mention other potential alternatives or broader context (e.g., when to use pull_request_number), so it falls slightly short of a 5.

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