update_promo_code

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

Annotations indicate non-readonly, non-idempotent, non-destructive. Description adds that it returns 404 on invalid IDs and that toggling enabled does not delete redemption history. This is useful but does not contradict annotations. It doesn't describe additional side effects or authorization needs.

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 reasonably concise, with clear sections for common use, error handling, args, and returns. The Args block repeats param names but is still efficient. Could be slightly more terse.

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?

Given the presence of an output schema, the description adequately explains returns. However, it omits the 'account' parameter and does not clarify partial update behavior (e.g., leaving fields null). For a 7-param tool with 0% schema coverage, the description should cover all 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?

The description provides clear explanations for most parameters (store_id, promo_rule_id, promo_code_id, code, redemption_url, enabled), including that code is case-insensitive. However, it misses the 'account' parameter present in the input schema, causing a slight gap. Schema coverage is 0%, so description compensates well 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 it updates a promo code's string, redemption URL, or enabled state, and explicitly differentiates from moving a code to a different rule (which requires delete and re-create). It distinguishes itself from sibling tools like create_promo_code and delete_promo_code.

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?

Provides a common use case (toggling enabled=false after campaign end) and a limitation (cannot move to different rule). Mentions 404 error for invalid IDs. However, it does not explicitly compare to update_promo_rule or other update tools.

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