chgrp

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

Annotations already declare destructiveHint=true, and the description adds context that it modifies 'filesystem group metadata' and offers dry-run as a safety measure. This goes beyond annotations without contradicting them. Could mention permission requirements, but overall strong.

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?

Four sentences, each adding distinct value: purpose, destructiveness, usage, and exclusions. No redundant or filler content. Efficient and well-structured.

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 tool with 4 parameters and no output schema, the description covers purpose, behavior, safety, and alternatives. It mentions return format briefly. Missing details on error conditions or permissions, but overall sufficient for decision-making.

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?

Input schema has 100% description coverage, so baseline is 3. The description mentions --dry_run and return JSON but adds little parameter-specific meaning beyond the schema. Adequate but not exceptional.

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 the tool changes file group ownership, mentions dry-run support, and explicitly distinguishes from sibling tools 'chown' and 'chmod' by stating what it does not do. This meets criteria for specific verb+resource and sibling differentiation.

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?

The description provides explicit when-to-use ('reassign group ownership') and when-not-to-use ('Not for changing user ownership — use 'chown'. Not for permission changes — use 'chmod'.'), along with a practical tip to use --dry_run for safe preview. This fully covers usage guidance.

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