card_upload_assetInternal bridge for the upload card (not for agents — use request_user_upload / upload_asset). phase 'presign' mints the PUT URL for the picked file; phase 'complete' verifies the object landed and finishes the request_user_upload call with the publicUrl.
| Name | Required | Description | Default |
|---|---|---|---|
| jobId | Yes | ||
| phase | Yes | ||
| file_name | No | ||
| projectId | Yes | ||
| size_bytes | No | ||
| content_type | No |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations provide readOnlyHint=false and destructiveHint=false, so the description does not need to repeat safety traits. The description adds the two-phase behavioral context (minting PUT URL, verifying landing, finishing request_user_upload) which is useful. However, it does not disclose side effects, permissions, or error behaviors beyond that. For a tool with these annotations, this is adequate but not rich.
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 concise and front-loaded with the critical warning that it is not for agents, then explains both phases efficiently. Every sentence earns its place, though it could be structured slightly clearer by separating the exclusion from the functional description.
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 6 parameters, no output schema, and zero param descriptions, an agent would struggle to invoke this correctly without additional hints. The description does clarify the purpose and phases, but leaves parameter semantics and return behavior unexplained. Given its explicit exclusion from agent use, the incompleteness is partially mitigated, but as a tool definition it is not fully complete for an agent that might still attempt it.
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 carries the full burden for parameter explanation. It mentions the 'picked file' and phases, but does not explain jobId, projectId, file_name, size_bytes, or content_type. The phase parameter is described indirectly ('presign'/'complete' roles) but not the others. The description fails to compensate for the lack of schema descriptions.
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 that this is an internal bridge for the upload card and explicitly warns it is not for agents, directing them to request_user_upload / upload_asset. It also details the two phases ('presign' and 'complete') with specific actions, making its function unambiguous and distinguishing it from siblings.
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 explicitly states when not to use this tool ('not for agents') and names the alternatives (request_user_upload / upload_asset). It also explains the two-phase usage flow, giving practical guidance on how the tool operates, which fully addresses when and when not to invoke it.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
Tools are mostly distinct, but there is some overlap among file-modifying tools (edit_file, write_file, apply_patch) and between run_code_in_vm and run_code_in_browser. Detailed descriptions and clearly scoped use cases help agents select correctly.
Most tools follow a verb_noun snake_case pattern (create_project, list_files, execute_sql), but a few deviate (apply_patch, card_upload_asset, run_code_in_vm). Overall readable and predictable, with only minor inconsistencies.
With 46 tools, the server exceeds the typical well-scoped range and approaches the extreme threshold. While the broad scope of a full development platform justifies many tools, this count may overwhelm agents and increase misselection risk.
The tool surface covers the full development lifecycle: project creation, file operations, database management, resource provisioning, deployment, testing, and debugging. Minor gaps exist (e.g., no delete_project or checkpoint management), but core workflows are well-supported.