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

Beyond the annotations it discloses meaningful operational context: other list members will see the item attributed to the user, the addition is not covered by the 24-hour plan undo (removal must happen in Zarok), and an editor/owner role is required. The request_id dedup note adds useful retry semantics; it sits in mild tension with idempotentHint=false, but because dedup depends on a caller-supplied key rather than the arguments being inherently idempotent, this is not a direct contradiction.

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 short sentences, front-loaded with the action before the operational caveats, with no filler. Density is high; nothing could be removed without losing 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?

For a mutation with no output schema, the definition covers role requirements, visibility, undo limits, and retry behavior, which is a solid baseline. It is still missing what a successful add returns (identifier, position, timestamps) and any meaning for the remaining five parameters.

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 0% across six parameters, so the description carries the full burden and falls short: only request_id gets any explanation ('a repeated request_id adds the item once'). Nothing is said about list_id, title, note, date, or priority semantics and constraints, all of which the agent must infer from raw patterns and enums.

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 opens with a specific verb and resource ('Adds one item to a shared list') and scopes it to a single item, so the agent immediately knows what the tool does. It does not explicitly name a sibling to contrast with, but 'add item' vs. zarok_set_shared_list_item_done / zarok_get_shared_lists is self-evident from the resource wording.

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 supplies a real precondition ('Requires an editor or owner role'), which helps decide whether the call will succeed. However, it never says when to prefer this over alternatives such as zarok_propose_changes or zarok_apply_changes, so the routing guidance is only implied.

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