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

Annotations already declare readOnlyHint=true, but the description adds a crucial behavioral guarantee: 'Never signs or broadcasts.' This goes beyond generic read-only semantics and clearly informs agents that this step only constructs unsigned fulfillment and does not send it to the network.

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?

Two compact sentences, front-loaded with the action and adding the critical safety caveat second. No wasted words; every phrase contributes to disambiguation or safety understanding.

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 simple 3-required-param schema, the presence of an output schema, and annotations covering the read-only behavior, the description provides sufficient context. It identifies the domain (Seaport fulfillment), the specific offer type (item/collection/trait NFH), and the boundary of the operation (no signing/broadcasting).

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?

The input schema already covers all three parameters with clear descriptions (EVM address, NFH token id, OpenSea order hash), so schema coverage is 100%. The description does not add additional parameter semantics, earning the baseline score.

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 clearly identifies the tool's action ('Prepare Seaport fulfillment'), its resource ('selected item, collection, or trait offer and matching NFH'), and explicitly distinguishes it by saying it 'never signs or broadcasts.' This separates it from signing/sending tools and from mainnet/internal accept variants, making the purpose unmistakable.

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?

The description gives a clear context for when to use it: when an NFH offer needs Seaport fulfillment prepared without signing or broadcasting. It does not explicitly cite alternative siblings like prepare_internal_accept_offer or prepare_mainnet_accept_offer, so exclusions are implied rather than stated, but the NFH focus provides enough guidance.

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