Retrieve a listing's public seller summary when available, with no login, phone lookup, or fallback on access denial.
Read public seller summary where available. No login, phone lookup or fallback on access denial.
| Name | Required | Description | Default |
|---|---|---|---|
| listing | Yes |
| Name | Required | Description | Default |
|---|---|---|---|
| data | Yes | ||
| warnings | No | ||
| schema_version | No | 1.0 |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly/idempotent/non-destructive/openWorld, so the description is not obligated to cover safety. It adds genuinely useful behavior: no authentication required, no phone lookup, and critically no fallback or retry when access is denied, which tells the agent not to expect alternative resolution paths.
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 tight sentences with zero filler; the core purpose is front-loaded ahead of the access/failure constraints. Every clause carries information.
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 not be explained, and annotations cover the safety profile. However, a required input parameter is left entirely undefined in both schema and description, which is a real gap for a single-argument lookup tool.
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 0% for the sole required parameter 'listing', and the description never mentions it. The agent cannot tell whether 'listing' is an ID, URL, address, or free-text query, so the description fails to compensate for the coverage gap.
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 (Read) and resource (public seller summary), and the 'seller' qualifier distinguishes it from the sibling dv_dealer_summary. The 'where available' scoping is a useful clarification, though it never says what entity the summary is resolved from.
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 implies usage through availability and failure constraints ('where available', 'no fallback on access denial') but never states explicitly when to choose this over dv_dealer_summary or dv_get_listing. Guidance is implied rather than stated.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.