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

Annotations already declare readOnlyHint=false, destructiveHint=false and openWorldHint=true, so the mutating, external-facing nature is covered. The description adds genuine state-transition context — the record starts as an unpaid draft and only reaches editor review once paid — but says nothing about what identifiers are returned, whether drafts expire, or what happens on duplicate submissions.

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 short sentences, front-loaded with the primary effect and followed by the workflow and writing constraints. The style directive ('no hype words, no claims you can't back') does affect how required description/tagline fields get filled, so it earns its place, but the phrasing is slightly informal for a tool spec.

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 an 18-parameter, 7-required creation tool with no output schema, the description covers the lifecycle but omits the return shape — notably that the resulting listing/order identifier is presumably what feeds create_payment. An agent must infer that linkage, which is a meaningful gap for a multi-step flow.

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 83%, so the schema already documents nearly every field including lengths, plan enum and category slug sourcing. The description only restates 'the chosen plan' and adds a content-quality rule rather than any per-parameter meaning, so the baseline of 3 is appropriate.

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 uses a specific verb and resource ('Creates the listing') and frames the two objects produced: an unpaid draft plus an order for the chosen plan. It also names the downstream sibling create_payment, so the agent can distinguish submission from payment, though it does not contrast with update_tool for editing an existing listing.

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?

It establishes the ordering of the workflow: submit first, pay later via create_payment, after which editor review begins. That gives clear conditions for when to call this versus the payment tool, but there is no explicit guidance on when not to use it (e.g., to modify an existing listing) and no mention that a plan should already be selected.

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