Encode text or binary data into standard or URL-safe Base64, with optional padding removal for URLs.
Encodes arbitrary text or byte data into standard RFC 4648 or URL-safe Base64 string representation.
| Name | Required | Description | Default |
|---|---|---|---|
| input | Yes | The plaintext string to encode into Base64 format. | |
| urlSafe | No | Optional boolean. Set to true to generate URL-safe Base64 (substitutes '+' with '-' and '/' with '_', omits padding). |
Changes observed during successful MCP inspections.
v1.0.2Input schema / properties / input / descriptionPrevious value: -"Plaintext string to encode"New value: +"The plaintext string to encode into Base64 format."Input schema / properties / urlSafe / descriptionPrevious value: -"Produce URL-safe Base64 format"New value: +"Optional boolean. Set to true to generate URL-safe Base64 (substitutes '+' with '-' and '/' with '_', omits padding)."v1.0.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are present, so the description carries the behavioral burden. It does disclose the output format and the RFC 4648/URL-safe distinction, which is helpful. It does not mention string encoding assumptions, padding behavior beyond what the schema says, or how byte data is represented, leaving some behavior unspecified.
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 a single, front-loaded sentence with no filler. It conveys the core purpose and the main variant in a compact, scannable way.
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 two-parameter encoding tool with high schema coverage, the description plus schema is largely sufficient. It signals the output type as a string representation, though a note on input encoding or padding could make it fully self-contained.
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%, so the input and urlSafe parameters are already documented in the schema. The description adds a general statement about encoding but does not materially refine the meaning of either parameter beyond the schema.
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 states a specific action ('Encodes') and a clear resource ('Base64 string representation'), and explicitly covers both standard and URL-safe variants. The direction of encoding is unambiguous and naturally distinguishes it from the sibling cyberchef_from_base64.
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 implies when to use the tool: when Base64 encoding is needed. However, it does not explicitly mention alternatives such as cyberchef_from_base64 or contrast encoding with decoding, so usage routing is left to inference rather than stated.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.