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

Goes well beyond the annotations: it clarifies that nothing is deleted despite destructiveHint=true (only the cascade relationship is severed), explains why it is both idempotent and destructive (no re-join), and specifies the 404 conditions for unknown, uneditable, or already-unlinked characters. This is exactly the behavioral context annotations cannot convey.

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-loads the core action, then layers consequences, reversibility, edge-case status codes, and return shape in tightly packed sentences with no filler. Every clause carries decision-relevant information.

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?

Covers the full picture for a one-parameter mutation: effect on the character, effect on siblings, irreversibility, error semantics, and return value (even restating it alongside the output schema). Nothing needed to invoke or interpret it correctly is missing.

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%, so the single 'id' parameter (Mongo _id, owner or admin scope) is already fully documented in the schema. The description references the `linkGroup` concept but adds no syntax or format detail beyond what the schema provides, so the baseline of 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?

States a specific verb and resource ('Remove one character from its linked-sheet group by clearing its linkGroup') and immediately distinguishes this from the inverse operation (vault_spawn_linked_character) and from list/link siblings. An agent can identify the tool's exact effect without opening 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?

Gives clear context for when this applies and names the alternative path for re-joining (a later vault_spawn_linked_character mints a NEW group), which steers the agent correctly. It stops short of explicit 'use this when / do not use this when' phrasing and does not contrast with vault_delete_character or vault_detach_companion, so it is strong but not exhaustive.

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