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

Annotations already declare read-only, idempotent, non-destructive, and the description repeats read-only. It adds useful behavioral details: sorting expiring-first, purpose semantics, url format, and a commission-related suggestion, going beyond the structured annotations.

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 two sentences plus an action-oriented tip. It is front-loaded with the core purpose and keeps extra guidance brief. Slightly awkward grammar but no wasted words.

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 list tool with no output schema, it explains the return items (codes with urls), sorting, and the purpose field. It omits what happens with the 'status' parameter and any pagination, but these are minor for this simple list.

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?

The description explains the 'purpose' parameter (share/gift) which the schema does not, but it leaves 'status' unexplained and only repeats that brand is a uuid. With schema coverage at 33%, it partially compensates but not fully.

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 lists Shopify discount codes for the current creator, sorted by expiry, and distinguishes it from singular alternatives like split_get_discount_code by emphasizing the plural scope and sorting.

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 gives context that it lists codes assigned to this creator, but it does not explicitly say when to use this tool versus alternatives like split_get_discount_code or other list tools. No exclusions or alternative names are mentioned.

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