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

Annotations already declare destructiveHint=true and idempotentHint=true, but the description adds substantial context beyond them: it specifies exactly what is destroyed (the group only, pages are ungrouped, not lost), warns of the 409 refusal on system groups, and points to a reversible sibling. This is unusually rich behavioral disclosure.

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?

Front-loaded with the action, then semantics, then the alternative, then the hard constraint. Every sentence earns its place despite the length; the corrective all-caps clause is justified because the naive assumption (deleting a group deletes pages) is the main risk.

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 need not be explained. Given a mutation tool with two required params and rich annotations, the description covers everything an agent needs to invoke it safely and 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 description coverage is 100% and both parameters are documented there, including the groupId source and the system-flag caveat, so the schema does the heavy lifting — baseline 3. The description mostly repeats this guidance rather than adding new syntax or format detail.

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 (delete a page group from the tab bar) and immediately clarifies scope by distinguishing it from what it is not — pages survive. An agent can tell this apart from xtiles_delete_page and xtiles_update_page_group 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 explicit when-to-use (safe tidy-up), names the alternative verb and exact parameter for the adjacent goal (xtiles_update_page_group with is_archived: true, reversible), and states a hard when-not (never target a group whose system flag is true). Nothing is left to inference.

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