> ## Documentation Index
> Fetch the complete documentation index at: https://praison.ai/docs/llms.txt
> Use this file to discover all available pages before exploring further.
# tool • Rust AI Agent SDK
> tool: The `#[tool]` attribute macro for defining tools. This macro transforms a function into a tool that can be used by agents. # Attributes -...
# tool
Function
> This function is defined in the [**praisonai\_derive**](../modules/praisonai_derive) module.
The `#[tool]` attribute macro for defining tools. This macro transforms a function into a tool that can be used by agents. # Attributes - `description`: A description of what the tool does (required for LLM understanding) - `name`: Override the tool name (defaults to function name)
```mermaid theme={"theme":{"light":"vitesse-light","dark":"vitesse-dark"}}
%%{init: {'theme': 'base', 'themeVariables': { 'primaryColor': '#8B0000', 'primaryTextColor': '#fff', 'primaryBorderColor': '#710101', 'lineColor': '#189AB4', 'secondaryColor': '#189AB4', 'tertiaryColor': '#fff' }}}%%
graph LR
agent["Agent"] -- "uses" --> tool["Tool: tool"]
tool -- "returns" --> result["Result"]
style tool fill:#189AB4,color:#fff
style agent fill:#8B0000,color:#fff
style result fill:#8B0000,color:#fff
```
## Signature
```python theme={"theme":{"light":"vitesse-light","dark":"vitesse-dark"}}
def tool(attr: TokenStream, item: TokenStream) -> TokenStream
```
## Parameters
No description available.
No description available.
### Returns
The result of the operation.
## Usage
```python theme={"theme":{"light":"vitesse-light","dark":"vitesse-dark"}}
use praisonai::tool;
#[tool(description = "Search the web")]
async fn search(query: String) -> String {
format!("Results for: {}", query)
}
// With custom name
#[tool(name = "web_search", description = "Search the internet")]
async fn my_search_fn(query: String, max_results: u32) -> Vec {
vec![format!("Result for: {}", query)]
}
```
## Uses
* `parser`
* `is_ident`
* `value`
* `parse`
* `error`
* `name`
* `unwrap_or_else`
* `path`
* `push_str`
* `trim`
## Source
`praisonai-derive/src/lib.rs` at line 46
***
## Related Documentation