Attach a file to a test run by providing base64-encoded content and a filename. Use this to document evidence or logs directly on the run.
Attach a file to a test run. Provide base64-encoded content.
| Name | Required | Description | Default |
|---|---|---|---|
| run_id | Yes | ||
| filename | Yes | ||
| content_base64 | Yes |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden. It only states that the tool attaches a file and that content must be base64-encoded; it does not disclose side effects, permissions, file size limits, overwrite behavior, or return 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?
Two short sentences deliver the core action and the key encoding requirement without filler. The description is front-loaded with the primary purpose.
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 three-parameter tool, the description is minimally adequate, but with no annotations and no output schema, an agent still lacks information about what happens on success or failure, response format, or any constraints beyond base64 encoding.
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?
With 0% schema description coverage, the description adds some meaning: content_base64 must be base64-encoded and run_id refers to a test run. However, filename and run_id semantics remain mostly implicit, and no additional constraints or formats are provided.
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 uses the specific verb 'Attach' with the resource 'file' and target 'test run,' making the tool's purpose immediately clear. This also distinguishes it from sibling tools like kiwi_add_test_case_attachment, which target test cases instead of runs.
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 clearly implies the tool should be used when attaching a file to a test run. It provides context but does not explicitly name alternatives or state when not to use this tool, so it stops 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.