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

Annotations already cover the safety profile (readOnlyHint, openWorldHint=false), yet the description adds real value: it discloses that SKILL.md text is returned only when the license allows it, and it pre-empts prompt injection by framing that text as data, not instructions. It does not say what happens for an unknown slug or an inaccessible license.

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 sentences, front-loaded with the core action and the payload inventory, then the safety caveat. No filler, and the injection warning is placed where a reader will reach it before using the output.

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 no output schema, the description usefully enumerates the returned fields and flags the conditional license dependency. The remaining gap is failure behavior — missing slug, unpublished skill, restricted license — which an agent would want to know before relying on the result.

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 required parameter at 0% schema coverage, so the description must carry the load. Saying 'by slug' establishes the identifier's role but not its format, source, or case sensitivity, which is the information an agent actually needs to form a valid call.

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 and resource — 'Full details for one skill by slug' — and enumerates exactly what comes back (install command, source link, license, safety scan, SKILL.md text). It implies the split with search_skills/check_skill through 'one skill' and 'full details', but never names a sibling to make the distinction explicit.

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?

Usage is only implied: fetch details once you already have a slug. There is no guidance on when to prefer this over check_skill or search_skills, and no stated precondition such as whether the slug must come from search results.

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