url_decode

Decode a percent-encoded URL string back to plain text. Follows RFC 3986 — %XX sequences are converted to the corresponding UTF-8 characters.

Parameters

Parameter	Type	Required	Description
input	string	Yes	The percent-encoded string to decode (e.g. "hello%20world" → "hello world").

Response

Field	Type	Description
decoded	string	Decoded plain-text string.

Examples

Input:

{
	"input": "hello%20world"
}

Result:

{
	"decoded": "hello world"
}

---

Input (query parameter values):

{
	"input": "key%3Dvalue%26other%3Dx"
}

Result:

{
	"decoded": "key=value&other=x"
}

---

Input (Unicode):

{
	"input": "h%C3%A9llo"
}

Result:

{
	"decoded": "héllo"
}

Errors

Each failure carries a precise code in the response. Argument-schema and server errors are JSON-RPC protocol errors; a rejected value is returned as a tool result with isError: true (so the agent can read the code and self-correct).

Code	When	Delivered as
invalid_arguments	An argument is missing or the wrong type.	protocol error (invalid_params)
invalid_percent_encoding	The input contains a malformed %XX sequence — the two digits are not valid hex (e.g. %GG) or the escape is truncated — or the decoded bytes are not valid UTF-8 (e.g. a lone high byte like %80).	tool error (isError)
internal_error	An unexpected server error.	protocol error (internal_error)

Notes

• This tool follows RFC 3986 percent-decoding. The + character is not decoded as a space — that convention belongs to application/x-www-form-urlencoded. A literal + in the input remains a + in the output.
• To encode a string, use url_encode.