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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the description's 'Read-only' is redundant rather than informative. It does add useful content shape (full body, version, hash, resource URI) that the annotations do not cover, warranting a mid score rather than higher.

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 front-loaded sentence that packs the resource, selector and payload contents with no filler. The trailing 'Read-only' is the one element that does not earn its place, since annotations already assert it.

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?

With an output schema present, full annotation coverage and a fully described single parameter, the description supplies everything needed to invoke the tool correctly. Its only shortfall is the absence of any usage routing relative to list/lookup siblings.

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?

One parameter with 100% schema description coverage; the schema already documents that 'id' is the exact id from studio_list_skills. The description's 'catalogue ID' phrasing adds no new syntax or constraint beyond the schema, 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?

The description names a specific verb ('Returns one') and resource ('Brix36 creative skill, style card or writing guide by catalogue ID'), so the action is unambiguous. Differentiation from the sibling studio_list_skills is only implied by the singular 'one ... by catalogue ID', not stated as an explicit contrast.

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?

It states what it returns but never says when to reach for it versus studio_list_skills, nor what to do if the ID is unknown. The only routing hint ('Exact id returned by studio_list_skills') lives in the schema, not the description.

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