Validate skin spec

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

The annotations already declare readOnlyHint and idempotentHint, so the safety profile is covered; the description adds two things they don't: no image rendering (no output artifacts) and low cost, which matters for an agent deciding to call this after every edit. It says nothing about error/warning severity or exit behavior, but the output schema covers the return shape.

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 short clauses, zero waste; the purpose lands first and the cost/usage hint second. Nothing here is a restatement of the name or title.

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 values need no explanation, and the schema fully documents both optional inputs. With annotations carrying the safety profile and the description carrying purpose plus call frequency, an agent has everything needed to invoke this 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?

Both parameters are optional with 100% schema description coverage, and the schema itself explains the file-vs-spec tradeoff and the texel_patch handoff far better than the description could. The description contributes nothing parameter-specific, so the baseline 3 applies.

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?

Specific verb and resource: "Check a spec for errors and warnings," with a scoping qualifier ("without rendering images") that implicitly separates it from texel_render. It stops short of naming a sibling, so an agent still has to infer that texel_render is the rendering alternative.

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?

"Use it after every edit" gives an explicit trigger for calling the tool, which is real usage guidance rather than silence. It offers no when-not-to-use condition and never names texel_diff or texel_render as the alternatives at the other end of the workflow.

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