data_uri

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

No annotations exist, so the description carries the full burden. It discloses build behavior (wrapping data with media_type, base64/percent encoding) and parse behavior (extracting media_type, parameters, is_base64, and decoded data). Minor gaps: no mention of error handling or side effects, but core behavior is transparent.

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, well-structured paragraph with line breaks. It front-loads the purpose, then uses bullet-style delineation for build and parse. Every sentence adds value; no 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?

Despite 7 parameters, no output schema, and no annotations, the description covers both modes completely. It specifies required inputs, optional fields, and parse output details (media_type, parameters, is_base64, decoded data). The tool's behavior is fully described for its intended use.

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 0%, so the description must compensate. It does so thoroughly: explains action, media_type, data, base64, uri, input_format, and output_format in context of each action, adding meaning (e.g., default media_type, parameters format) beyond the raw 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 opens with a specific verb-resource pair: 'Build a data: URI from a payload, or parse one into its parts (RFC 2397).' It clearly distinguishes two distinct actions, and the subsequent details reinforce purpose without ambiguity.

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 explains two modes (build vs. parse) but offers no explicit guidance on when to use this tool over siblings like encode/decode or bytes_edit. The context for each action is clear, but exclusions and alternatives are missing.

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