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

With no annotations provided, the description carries the full behavioral burden. It reveals that this is a tenant-bound loopback adapter, that the Meta-owned MMP service is the source of truth, that the server scopes to a fixed channel_pid, and it clarifies the potentially confusing 'adset' mapping. It does not mention rate limits, data freshness, or error behavior, but for a read operation the key behavior is well 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?

The description is dense yet efficient. It front-loads the core purpose, adds essential context (adapter, scope, fan-out disclaimer), then provides requirements and an example. Every sentence adds value, and the structure guides the reader logically.

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 tool's simplicity (read operation, 3 parameters, no output schema), the description covers all essential aspects: purpose, parameter provenance, breakdown options, and a usage example. It lacks edge-case guidance (e.g., behavior when no data exists for today), but that is a minor gap for a read-only aggregate endpoint.

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 0%, so the description must compensate. It does so fully: it gives provenance for product_id and event_name, lists all breakdown enum values, and explains the adset nuance ('maps to TikTok's native ad_group role; it is not a Meta ad set'). The example further clarifies the expected payload.

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 states a clear verb ('Read'), a specific resource ('today's AppsFlyer count, unique-user, and revenue aggregate for one saved product and event'), and a precise scope ('scoped by the server to channel_pid=tiktokglobal_int'). It explicitly differentiates from siblings by noting 'It does not perform client-side fan-out', making its purpose unambiguous.

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 strong usage context: where to obtain required parameters ('product_id (from products_list), event_name (from products_get_actions)'), the optional breakdown options, and a concrete example invocation. It implies exclusions via the adapter/fan-out note, but does not name alternative tools explicitly or state conditions when not to use it, so it falls short of a 5.

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