Code completion versus coding agents: suggestions and task execution differ
Compare editor completions with agents that modify and validate code, using one repair task to assess context, scope and acceptance effort.
Choose an approach
Use completion for local suggestions while writing a function; consider a coding agent when the task requires finding files and running checks. Both can coexist in an editor, so interface names do not establish capability. Verify the actual requirement: generated code and executed commands are not proof that the defect is fixed.
Local suggestions and tool execution have different boundaries
GitHub’s IDE guide covers both suggestions and agent mode, which can find code, edit and run commands. Context and tools depend on configuration; completion need not see only one line, and an agent does not automatically understand the whole project. Parameter changes may affect many callers. Developers must follow those effects with completion, while agents can still miss dynamic references. Define scope from requirements rather than autonomy claims.
Compare the entire process on one repair task
Fix a repository commit and failing input for both methods. Record files the developer locates with completion and actual diffs and checks from the agent. Recheck the original failure and a neighboring valid case. Count manual changes and clarification time, not generation speed alone. Missing dependencies mean tests remain unverified; suggested tests are not execution records. Apply the same standard to completion-generated tests.
Maintain tool permissions and project validation guidance
Start small with local suggestions and expand delegation for cross-file work. Give agents build entry points and excluded files, retaining the original version to detect unrelated changes. After completion-plugin updates, check compatibility with formatting and existing interfaces. Include calls and review across the task; accepted suggestions are not completed tasks. This is a documentation-based comparison, not a coding benchmark or measured speed claim.
Checked sources
These sources support the concepts and methods described here. Examples and test scope are labeled separately; check the version of the tools you use.