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

Annotations already declare readOnlyHint/idempotentHint/non-destructive, so the safety profile is covered. The description adds real value beyond that by disclosing the exact return payload (authority requested, publisher trust signals, install command) and asserting completeness ("Everything needed ... arrives in this one call"). It doesn't mention error behavior for unknown skill ids or version fallback beyond the schema default.

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 the primary action and the preflight trigger front-loaded. The closing "Everything needed to decide whether to trust a skill arrives in this one call" is slightly promotional but does reinforce that no follow-up call is needed.

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 carries the return-value burden and does so by enumerating what the caller gets. Annotations cover the safety profile, so the only unaddressed edge is failure/not-found behavior, which is minor for a 2-parameter read.

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%, including the `publisher/name` format example and the version default, so the description is not required to compensate. It adds no syntax or format detail beyond that baseline.

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+resource ("Read one runx skill in full") with an enumerated payload (manifest, authority, publisher/trust signals, install/run command). The singular "one skill" scopes it against the sibling search_skills, so an agent can route without opening either schema.

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?

Gives a clear trigger: read this "before running it," framing the tool as a trust/inspection preflight step. It never names search_skills as the alternative or states when-not to use this tool, so it stops short of explicit routing.

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