group_set

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

With no annotations provided, the description carries the full burden and discloses key behavioral traits: batch operation, replacement of existing groups, addition of new ones, and automatic rejection of default-skills. It doesn't cover permissions or failure modes, but the essential side effects are well communicated.

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?

The description is exceptionally concise: three sentences that front-load the primary action, with each sentence providing distinct, valuable information—operation, batch behavior, and the rejection rule.

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?

For a two-parameter tool with no output schema, the description covers the core functionality, important edge cases (default-skills rejection), and behavioral semantics. No critical operational aspects are missing for an agent to invoke it 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?

Schema coverage is 100%, but the description adds meaning beyond the schema field names: it specifies batch semantics for the 'groups' parameter and explains the replace/insert behavior. This enriches the understanding of how the parameters are used.

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 clearly states a specific action and resource: 'Writes the group field in SKILL.md frontmatter' and describes batch mapping. It distinguishes from sibling group_list by indicating a mutation operation versus a read operation.

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 provides clear context for use: batch update of skill-to-group mappings with replace-or-insert semantics. It doesn't explicitly name alternatives, but the action's scope is unambiguous and the rejection of default-skills serves as an implicit when-not-to-use signal.

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