Retrieve a listing owner's price observations from first record to track how asking prices changed over time; not a retroactive market index.
Return this owner's observations of this listing, starting at first observation. It is not a retroactive market index.
| Name | Required | Description | Default |
|---|---|---|---|
| limit | No | ||
| 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 readOnlyHint, idempotentHint, and openWorldHint, so the safety profile is covered. The description adds one genuinely useful behavioral fact — results are ordered from the first observation — but says nothing about pagination or how the limit caps the series.
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, with the scope statement front-loaded ahead of the disambiguation. No filler, though the terse phrasing leaves the critical listing-identifier semantics unaddressed rather than merely brief.
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 safety. However, the caller must supply a 'listing' identifier and a 'limit' with no guidance on either, which is the main completeness gap for an otherwise simple read 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 both parameters, so the description carries the full burden and does not meet it. It never explains the format of 'listing' (ID? URL? address?) nor what 'limit' (default 90, max 100) bounds — number of observations, days, or pages.
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 and resource ('Return this owner's observations of this listing') plus a scope qualifier ('starting at first observation'). The closing clause implicitly distinguishes it from dv_market_history, though it never names the sibling it is not.
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 negative framing ('It is not a retroactive market index') implies the alternative exists but never names it or states a positive when-to-use condition. An agent can infer the tool returns owner-recorded observations rather than market data, but must guess at the boundary versus dv_market_history or dv_get_listing.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.