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

Goes well beyond the annotations (readOnlyHint=false, idempotentHint=false, destructiveHint=false) by disclosing the one-time API key return, the default pending_review state, the functional consequence (can publish/register but not surfaced in search), and the approval-bypass behaviour of invite_code. These are exactly the traits an agent cannot infer from structured fields.

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 tightly packed sentences, front-loaded with the core action, then the one-time-secret warning, then the state machine, then the invite_code caveat. No filler and every clause carries operational weight.

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?

An output schema exists so return values need little explanation, yet the description still flags the critical 'shown once' property. Account state, search visibility, and the invite_code escape hatch together give an agent everything needed to invoke this correctly.

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 60% and the schema itself already documents slug, description, and invite_code semantics. The description reinforces invite_code's purpose and adds approval-bypass context, but says nothing about org_name or contact_email, so it only marginally exceeds what the schema provides.

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+resource ('Create a new marketplace seller account') that is clearly distinct from every sibling (seller_publish_document, seller_register_endpoint, list_partners, etc.). The account-state explanation further pins down exactly what resource is being created.

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?

Explains the context in which this tool is used (new seller onboarding) and the condition for the invite_code path ('if the operator gave you one'). It does not name a competing tool, but none of the siblings is an alternative to signup, so there is little left to disambiguate.

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