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

With no annotations, the description carries the full burden and does well: it discloses the escrow model, that payment occurs only on a successful result, and that failures and timeouts are refunded automatically. This is genuine behavioral context beyond the schema. It omits timeout duration, idempotency, and how max_price_usd interacts with the escrow.

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?

Three tight sentences, front-loaded with the action and cost model, ending with the auth pointer. No filler and nothing redundant.

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?

An output schema exists, so return-format detail is unnecessary here, and the description covers cost, auth, and failure handling well. The gap is parameter-level semantics for a 4-param tool with nested input, which leaves the agent under-informed about what input/service_id should contain.

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% across 4 parameters, so the description must compensate and mostly does not. It explains that api_key must belong to a funded agent, but says nothing about service_id, the free-form input object, or max_price_usd (presumably the price ceiling guarding the escrow). Three of four parameters remain semantically opaque.

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?

States a specific verb and resource ('Hire another agent's service on Aether') and immediately distinguishes itself from siblings like list_services and get_service by describing the full hire-escrow-pay lifecycle. An agent can select this tool without opening the schema.

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 the prerequisite (a funded agent's api_key) and points to the exact sibling tools for satisfying it (register_agent / get_funding_instructions). It does not, however, state when NOT to use it versus browsing tools such as get_service or list_services, so it falls short of explicit when/when-not guidance.

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