meta_ads_conversions_send_purchase

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

Despite no annotations, the description discloses critical behaviors: returns an acknowledgement, is a mutating operation, and provides details on automatic hashing of PII fields. It also explains the test_event_code routing, covering important behavioral traits.

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 efficient: two sentences that front-load the purpose, followed by sibling differentiation and a note on required fields. Every sentence contributes meaning without redundancy.

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 description covers the main intent, return value, key parameter behavior (hashing), test event usage, and alternative tools. It is complete for a single-event send tool, even without an output schema.

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 100%, so baseline is 3. The description adds value by summarizing required fields as 'amount, currency, and hashed user identifiers' and explaining the hashing behavior, which goes beyond 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?

The description clearly states the tool sends a single Purchase event via the Meta Conversions API, and explicitly distinguishes from siblings by naming alternative tools for other event types. It also provides context that this is the most common CAPI use case.

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 explicitly tells when to use this tool (for Purchase events) and when not (for leads or custom events), directing to alternatives. It also implies usage context by stating it's the most common use case, giving clear guidance to the agent.

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