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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds real behavioral detail beyond them: exactly which artifacts come back (definition, SKILL.md path, per-client install commands, Grok Bot install message) and that include_body returns trimmed SKILL.md text.

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 tight sentences with the resource and key payload front-loaded and no filler. The client enumeration makes it slightly list-heavy, but each clause conveys a distinct return element rather than padding.

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 needn't be spelled out, and the description still sketches them. However, for a tool whose whole value is the returned install artifacts, it omits how response_format changes the result and gives no hint about failure when a slug is unknown.

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 coverage is 100%, so slug, include_body and response_format are already documented, including the 6,000-character trim and the enum. The description restates include_body's effect but adds no semantics beyond the schema and says nothing about response_format, so 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 states a specific verb and resource ('One skill by slug') and enumerates the payload — behavior, SKILL.md location, install commands per client, and Grok Bot chat message. It is clearly distinct from a plural search, but it never names search_skills as the sibling that supplies the slug, leaving that routing link to the 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?

Usage is only implied: an agent infers it should call this once it has a slug, and the schema text ('Skill slug from search_skills') carries the prerequisite. The description itself offers no when-to-use or when-not-to-use statement and no alternative paths.

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