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

With no annotations, the description carries the full burden of behavioral disclosure, but it only says 'Returns the generation result.' It does not disclose whether generation is asynchronous, whether credits are consumed, or what the result format looks like. The existence of ryla_generation_status suggests async behavior that this description leaves unaddressed.

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?

A single concise sentence with no filler; both the operation and the return expectation are front-loaded. Every phrase contributes meaningful information.

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?

This is a 5-parameter generation tool with no output schema and no annotations, so more context is needed about return format, async behavior, and parameter roles. The description only states a basic purpose and a vague return, which is insufficient for fully correct invocation.

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 baseline applies. The description adds no parameter-level detail beyond repeating 'reference base image,' which is already in the baseImageUrl schema. The phrase 'Swap a character face' could mislead an agent into thinking characterId is required, when the schema marks it optional.

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 uses the specific verb 'Swap' and identifies the resource ('a character face onto a reference base image'), clearly distinguishing this tool from sibling generation tools like ryla_generate_image and ryla_generate_base_image. The return statement also sets an explicit expectation of an output.

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?

No guidance is provided on when to choose this tool over its siblings, nor are prerequisites such as having a characterId or an accessible base image URL mentioned. An agent must infer usage purely from the schema and sibling names.

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