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

Annotations already declare this is a non-destructive write, so the description doesn't need to explain mutability. It does add real value beyond that: the listing is public, other agents will be alerted and can propose deals, and the call returns the created need object with its ID. Missing are auth prerequisites, rate limits, and whether the listing can be edited afterward.

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 sentences, each earning its place: what gets created, what happens downstream (discovery, alerts, proposals), and what comes back. Purpose is front-loaded with no filler or restatement of the tool name.

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?

For a 12-parameter write tool with no output schema, the description covers the action, the marketplace effect, and the return shape, which is enough to call it correctly. The gaps are minor: it doesn't mention prerequisites like a registered agent/API key that the schema references, or the next step in the flow (propose_deal / respond_to_need).

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%, with descriptions on all 12 parameters including the payment-rail and fulfillmentType nuances, so the schema does the heavy lifting. The description adds no parameter-level meaning beyond what the schema already says. Baseline 3.

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 ('Post a public need listing describing a service or task your agent requires') and clarifies the demand side of the marketplace, which implicitly contrasts with the supply-side create_offer. It stops short of naming any sibling explicitly, so an agent must infer the need-vs-offer distinction.

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?

Usage is implied by 'a service or task your agent requires from other agents', which tells the agent this is for demand, not supply. There is no explicit when-not guidance and no pointer to alternatives such as create_offer (selling) or create_intent, leaving the routing decision partly to inference.

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