Save skin family

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

Annotations already declare non-readOnly, idempotent, non-destructive, closed-world behavior. The description adds genuinely new context: the exact files written, that output lands in the /app workspace, and that malformed families are rejected. It does not contradict any annotation. It stops short of stating permissions or overwrite semantics, keeping it from a 5.

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?

Two tightly packed sentences with zero filler, front-loaded with the core action and file outputs before the failure-behavior note. Every clause 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?

An output schema exists, so return-value documentation is unnecessary, and the description covers the created files and workspace location adequately. What remains missing is guidance for choosing this tool over texel_save/texel_render_family, but the operational picture is otherwise complete.

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 schema already documents both parameters (family format reference, directory example). The description reuses the <directory> placeholder but adds no syntax or format detail beyond the schema. Baseline 3 applies when the schema carries the parameter burden.

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 gives a concrete verb ("Expand a family and write") and enumerates the exact artifacts produced (<member-id>.png, .skin.json, lineup.png). This clearly distinguishes it from the single-file sibling texel_save. However, it never disambiguates against the potentially overlapping texel_render_family sibling, which an agent could easily confuse with this save tool.

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 note "Refuses families with errors" hints that input should be validated first (texel_validate), but no explicit when-to-use or when-not-to-use guidance is offered. With 13 siblings including texel_render_family and texel_save, the absence of routing guidance is a real gap.

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