ga_send_purchase

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

Annotations already indicate a write operation via readOnlyHint=false. The description adds that it sends data externally to Google Analytics, which is useful but largely redundant with the tool name and sibling context. No additional behavioral caveats like auth needs, deduplication, or rate limits are disclosed.

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?

Two concise sentences, front-loaded with the primary action. Every word adds value, and it does not restate schema 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?

The tool has 11 parameters and nested objects, but the schema is rich with descriptions. The description clearly defines the event purpose and when it should fire, which is sufficient for a competent agent given the sibling tools and schema context. It could mention duplicate protection or user identification but is not lacking enough to drop below 4.

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 82%, so the schema already documents most parameters. The description only generically mentions 'transaction details and items' without adding specifics about required fields or nested item structure, so it doesn't compensate for the remaining undocumented parameters.

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 sends an ecommerce purchase event to Google Analytics, specifically for tracking completed purchases. This distinguishes it from sibling tools like ga_send_event, ga_send_begin_checkout, and ga_send_add_to_cart.

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 provides clear context that this is for completed purchases with transaction details and items, implying use at purchase completion. It doesn't explicitly name alternative tools for other funnel stages, but the 'completed purchases' wording offers sufficient guidance.

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