update_promo_rule

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

Discloses partial update behavior ('Only provided fields are changed'), error return (404 if invalid IDs), and typical use cases. Annotations (readOnlyHint=false) align with mutation. Adds value beyond 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?

Concise opening, followed by usage paragraph, return info, and structured Args list. No wasted sentences, front-loaded with purpose.

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 behavior, parameters, return format, error handling, and use cases. Output schema exists but not detailed; description says 'Returns: JSON with...' which is sufficient. Missing 'account' parameter mention reduces completeness slightly.

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 coverage is 0%, but description lists all 10 parameters (missing 'account' from schema) with brief explanations (e.g., 'type: New type ('fixed' or 'percentage')'). Compensates well for lack of schema descriptions.

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?

Description clearly states 'Update an existing promo rule' and provides example use cases like toggling enabled, extending end date, adjusting amount. Distinct from siblings like create_promo_rule, delete_promo_rule, and list_promo_rules.

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 when-to-use scenarios (toggle rule, extend end date, adjust amount) and references list_promo_rules to find IDs. Does not explicitly state when not to use, but context is clear.

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