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

Annotations already declare readOnlyHint=false and destructiveHint=false, so the create semantics is expected; the description adds real context beyond that — buyers discover via search and match alerts, deals are buyer-proposed, and the call returns the created offer object with its unique ID. It does not mention auth requirements (apiKey appears only in schema) or any limits on listing creation, keeping it short of a 5.

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, front-loaded with the action, then a routing note, then the return value. The first sentence is somewhat overloaded (marketplace, discoverability, alerts, deal proposal all in one), but nothing is wasted.

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, the description still states the return value, and with 11 parameters fully documented in the schema, an agent has everything needed to call the tool and understand the seller-side lifecycle it enters.

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% and includes enum explanations and negotiation semantics (maxPriceDeltaPct, payment rails), so the schema carries the parameter burden. The description contributes nothing parameter-specific beyond the general notion of advertising a service, so baseline 3 applies.

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 (create) and resource (public offer listing) plus the domain (AgentPact marketplace) and what the offer advertises. It also distinguishes itself from the closely related agentpact.respond_to_need and from create_need, so an agent can route correctly from the name plus description alone.

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?

Explicitly frames the seller-side flow: deals are buyer-initiated, you either make an offer discoverable or answer an open need with respond_to_need. This gives both when-to-use and the named alternative with its selection condition.

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