Create Files in Existing Project

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

Beyond the annotations (readOnlyHint=false, destructiveHint=false, idempotentHint=true), the description adds important behavioral context: files are created relative to the given directory, and the operation can skip or error on files. It also mentions the return summary, which is not visible in annotations. This adds meaningful transparency without overstating side effects.

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 well-structured with clear sections for Args, Returns, and an Example. It is moderately concise and avoids excessive verbosity. The example is particularly useful but adds some length; still, every part contributes to understanding the tool.

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 tool's moderate complexity (3 parameters, nested array, overwrite behavior) and the presence of good schema and annotations, the description is complete enough. It explains the tool's purpose, return type, and operational constraints (relative paths, no new folder creation). The absence of an output schema is compensated by the explicit return description.

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 already has 100% coverage with clear descriptions for all parameters. The description reinforces these by listing them in an Args block and providing a concrete example call. The example clarifies the structure of the nested 'files' array, which is valuable beyond the schema's property definitions.

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: 'Add files to an existing project directory.' This is a specific verb (add) and resource (files) that distinguishes it from sibling tools like scaffold_create_folders and scaffold_create_project. The explicit note 'Does not create a new project folder' further differentiates it from the project-creation sibling.

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 clear context for when to use the tool: to add files to an existing project directory. It also states a when-not condition ('Does not create a new project folder'), but it does not explicitly name an alternative sibling tool. This is slightly below level 5 because alternatives are not directly referenced, but it still offers solid usage guidance.

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