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

Annotations already cover read-only/idempotent/destructive/openWorld, and the description adds genuinely new context: it never sends the request, evaluates nothing itself, is deterministic, and requires no payment or account. It stops short of describing the shape or limits of the returned `send` structure.

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?

Purpose is front-loaded and the piece is compact, with each clause carrying information about inputs or outputs. The middle sentence is dense and slightly tangled ('with the free paths (MCP, and REST when the verifier says so) and the paid path'), which costs a little readability.

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?

With no output schema and 7 parameters, the description usefully sketches the return payload (`request_body` filled once, plus `send`), which annotations cannot convey. Remaining gaps (trace_id continuation, task_id/agent_id roles, `send` structure) are covered by the schema, so an agent has nearly everything needed.

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 100%, so the schema already documents all 7 parameters, including the listing_id/output_schema exclusivity. The description only restates that either listing_id or an inline output_schema is given, adding no syntax, format, or trace-continuation detail beyond the schema.

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 names a specific verb+resource ('Prepares the exact call to the Agent Output Verifier for one output') and enumerates what is produced (`request_body` and `send` with free/paid paths). It is clearly not the verifier itself, but it never names a sibling tool as the alternative, so the differentiation from the rest of the toolset is left implicit.

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 gives a real selection rule for the inputs ('Give listing_id (its template) or an inline output_schema') and states it 'never sends the request', implying a prepare-then-send workflow. However, it never says when to prefer this over a tool that actually sends or evaluates, and offers no explicit when-not guidance.

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