Checks saved Facebook Marketplace monitors for new listings since the last check. Optionally target one monitor by name or omit to check all.
Check saved monitors for new listings since last check
| Name | Required | Description | Default |
|---|---|---|---|
| monitor_name | No | Check a specific monitor by name, or omit to check all |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries full burden. It implies a read-like operation but does not disclose if the tool modifies state (e.g., updating last-checked timestamp) or any side effects, which are critical for an agent.
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?
The description is a single sentence with no excess words, perfectly concise for the tool's simple purpose.
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?
The tool is simple (1 optional param, no output schema), but the description lacks details on return value, behavior of 'since last check,' and side effects. It is adequate but not fully complete.
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 100%, with the parameter 'monitor_name' described clearly. The description adds no further meaning beyond the schema, but it is not needed given full coverage.
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 clearly states the verb 'Check' and the resource 'saved monitors' for new listings since last check, distinguishing it from siblings like 'list_monitors' (simple listing) and 'search_listings' (direct search).
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 provides no guidance on when to use this tool versus its siblings (e.g., list_monitors, search_listings) or when not to use it. No exclusions or context are mentioned.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.