Triggers a new EAS build using a build profile from eas.json. Requires a GitHub repository to be connected to the project. Provide either appId (from app.json "extra.eas.projectId") OR appFullName (e.g., "@owner/my-app").
| Name | Required | Description | Default |
|---|---|---|---|
| appId | No | ||
| gitRef | Yes | ||
| platform | Yes | ||
| autoSubmit | No | ||
| appFullName | No | ||
| buildProfile | Yes | ||
| baseDirectory | No | ||
| submitProfile | No |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotation contradiction: openWorldHint=false conflicts with the description's 'Triggers a new EAS build' and GitHub prerequisite, which imply interaction with external EAS/GitHub services. The description also does not disclose side effects such as queuing, cost, or asynchronous build behavior.
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 two front-loaded sentences with no filler. Every clause adds meaningful information about purpose, prerequisites, and parameter selection.
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?
With 8 parameters, no output schema, and no parameter descriptions, the description is far from complete. It leaves required gitRef semantics unclear and creates ambiguity around appId/appFullName despite schema marking them optional.
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 0%, so the description must compensate. It only clarifies appId and appFullName, while the required gitRef and other parameters such as autoSubmit, baseDirectory, and submitProfile remain undefined.
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?
Clearly states it triggers a new EAS build using a build profile from eas.json. This distinguishes it from sibling tools like expo_build_cancel, expo_build_list, and expo_build_logs.
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 clear usage prerequisites: a connected GitHub repository and either appId or appFullName. It does not explicitly name alternatives or when-not-to-use cases, but the context is sufficient for basic selection.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.