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

The description goes beyond the annotations by stating the key behavioral guarantee: it returns unsigned calls and never signs or submits them. This is valuable because it clarifies the transaction workflow and confirms there is no side effect, consistent with readOnlyHint and destructiveHint.

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?

The description is two concise sentences. It front-loads the operation and resource, then immediately clarifies the important safety boundary. There is no redundancy or irrelevant detail.

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 presence of an output schema, a fully covered input schema, and annotations that already indicate a read-only, non-destructive operation, the description is complete. It adds the only missing context: that this prepares an unsigned call and does not execute it.

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?

Input schema coverage is 100%, and both parameters are documented as EVM address and NFH token id. The description itself does not add parameter-specific semantics, but it does not need to because the schema already covers them adequately.

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 states the tool's function: 'Prepare cancelListing()' for a specific verified mainnet marketplace. It distinguishes the tool from siblings like prepare_internal_cancel_listing and prepare_mainnet_cancel_offer by naming the exact operation and network.

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 clearly signals that this is a preparation-only step—'Returns unsigned calls; never signs or submits'—which tells an agent when to use it in a workflow. It does not explicitly state when not to use it or compare it to the internal-cancel sibling, but the mainnet qualifier gives enough contextual direction.

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