encode_base64

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

With no annotations, the description carries the behavioral burden. It discloses that image encode returns a dataURL, image decode writes to a file (with output_path required), and text mode processes strings. However, it fails to clarify how the required 'text' parameter is used in image mode, leaving ambiguity about the image source path or base64 input.

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—two compact sentences—yet conveys all key behaviors: modes, actions, and side effects. It is front-loaded with the core purpose and contains no unnecessary words.

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 complexity (4 parameters, multiple modes, side effects) and lack of output schema/annotations, the description covers the main flow but omits details like the return value for decode, the ambiguity of 'text' in image mode, and the schema discrepancy where output_path is required by description but not marked required in the schema.

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 only 25% (output_path). The description adds meaning to 'mode' and 'action' enums and clarifies output_path's role, but it does not define the semantics of 'text' in image mode. This partially compensates for the low coverage but leaves a critical parameter underdocumented.

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 tool performs Base64 encoding/decoding, with explicit modes for text and image operations. It distinguishes itself from sibling encoding tools by specifying the Base64 algorithm and detailing mode-specific behaviors (text vs image, encode vs decode).

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 clear context for when to use each mode: mode=text for strings, mode=image for local image conversion. It does not explicitly mention alternatives or when not to use the tool, but the mode breakdown effectively guides usage.

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