Track a saved classifieds search: return only listings posted since your last check; the first run records a baseline and returns all current results.
Return listings that appeared since the last check of a saved search.
The first check records a baseline and returns everything currently listed.
| Name | Required | Description | Default |
|---|---|---|---|
| name | Yes | ||
| max_pages | No |
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With only openWorldHint in annotations, the description carries most of the burden and does disclose the key non-obvious trait: this tool is stateful, and the first invocation behaves differently (baseline + full return) from subsequent ones. It omits anything about pagination limits or failure modes for unknown names, so it stops short of full coverage.
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 core behavior and followed by the one edge case that would otherwise surprise a caller. No filler, no restatement of the tool name.
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-value detail is rightly omitted, and the stateful first-check behavior is covered. However, for a tool whose schema is entirely undocumented, leaving max_pages and the meaning of 'name' unexplained is a real gap an agent would hit at invocation time.
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. The description never mentions the required 'name' parameter or explains that it identifies the saved search, and 'max_pages' (default 2, max 5) is completely unaddressed despite directly governing result volume. A 0%-coverage schema needed the description to compensate and it does not.
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 listings') scoped to a saved search's check history, which cleanly separates it from siblings like search_listings, get_listings, and list_saved_searches. It does not name an alternative explicitly, but the resource qualifier does the differentiation work.
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 first-check semantics ('records a baseline and returns everything currently listed') give useful implied guidance about state and expected results, but there is no explicit when-to-use versus search_listings/get_listings, nor any prerequisite about the saved search needing to exist first.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.