Upload File

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

Annotations cover key traits (readOnlyHint=false, destructiveHint=false, etc.), but the description adds valuable context: it discloses that the tool returns a public URL and mentions the server fetches the file from a URL, which isn't obvious from the schema alone. It doesn't contradict annotations (e.g., 'Upload' aligns with readOnlyHint=false). However, it could add more on rate limits or auth needs, so it's not a full 5.

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 front-loaded with the core purpose and return value, followed by usage examples, all in two concise sentences. Every sentence adds value: the first states what it does and returns, the second provides context. There's no wasted verbiage or redundancy.

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 (upload with 2 params), rich annotations, and no output schema, the description is fairly complete: it covers purpose, return value, and usage examples. However, it could be more comprehensive by explaining error cases or the public URL's format, but annotations help fill gaps. It's not perfect but sufficient for most use cases.

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 100%, with clear descriptions for 'file_url' and 'folder'. The description doesn't add any parameter-specific details beyond what the schema provides (e.g., no extra syntax or format info). According to rules, with high schema coverage, the baseline is 3, and the description doesn't compensate further, so it earns a 3.

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 action ('Upload a file') and resource ('to DUAL storage'), and specifies the return value ('Returns a public URL'). It distinguishes from siblings like 'dual_get_file' or 'dual_delete_file' by focusing on creation rather than retrieval or deletion. However, it doesn't explicitly differentiate from all upload-related siblings (none listed), so it's not a perfect 5.

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 implied usage context with 'Useful for template assets, face images, and attachments,' which suggests common scenarios. However, it lacks explicit guidance on when to use this tool versus alternatives (e.g., no mention of when to use 'dual_create_face' for face images instead), and doesn't specify prerequisites or exclusions. This is adequate but has clear gaps.

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