convert

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

With no annotations provided, the description carries the full burden. It discloses non-destructive behavior (source unchanged), alpha flattening onto white for non-transparent formats, and the return value (output path and final format). This is substantial, though it doesn't cover error cases or overwrite semantics, which are minor for this simple tool.

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 well-structured and front-loaded, with the core purpose in the first sentence. Each subsequent sentence adds specific critical details (format inference, alpha handling, return) without repetition or filler. Every sentence earns its place.

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 conversion tool with no output schema or annotations, the description covers the key aspects: purpose, input/output, behavioral quirks, and result. It lacks details on error scenarios or handling of existing output files, but these are not essential for basic invocation. The description is complete enough for an agent to use it correctly.

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 covers all parameters (100% coverage), so baseline is 3. The description adds value beyond the schema by explaining the inference of format from the output extension and the alpha-flattening behavior tied to format choice. This enriches understanding of 'format' and 'out' parameters, pushing slightly above baseline.

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?

States a specific verb ('Change an image's file format') and resource (image), with the outcome of writing to a NEW file and source unchanged. Clearly differentiates from siblings like resize/crop by focusing on format conversion. The purpose is unambiguous.

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 usage (format conversion) but does not explicitly contrast with alternatives or state when to use this over siblings. No 'when to use' or 'when not to use' guidance is provided. It's clear from the name and purpose, but not explicit.

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