Save an immutable marketplace listing draft for 30 minutes and display a summary with a confirmation button, without contacting Vinted; edits require a new draft and renewed confirmation.
Save an immutable listing for 30 minutes and show summary and confirmation button. Does not contact Vinted. Any edits require a new draft and renewed confirmation.
| Name | Required | Description | Default |
|---|---|---|---|
| listing | Yes |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Adds real behavior beyond the annotations: a 30-minute TTL, immutability of the saved listing, no external side effects (annotations already flag openWorldHint=false, and the description reinforces it), and that edits invalidate the confirmation. Missing is what happens on expiry or whether a stale draft must be cleaned up, so it is not complete.
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 sentences, zero filler. The most decision-relevant fact (no Vinted contact, immutable, 30-minute window) is front-loaded and the edit/confirmation rule follows immediately.
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 lifecycle behavior is well covered for a mutation tool, and there is no output schema to explain. But with a large, undocumented nested parameter object and no annotation-level detail about failure modes, the definition leaves an agent guessing about how to construct valid input.
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 a nested Listing object with 16 properties, many of them required IDs (catalog_id, brand_id, status_id, package_size_id) whose meaning and valid source is entirely unexplained. The description adds nothing about any field, so the agent gets no help on the hardest part of invoking this tool.
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 (save an immutable listing) plus the concrete user-facing effect (show summary and confirmation button). The line 'Does not contact Vinted' cleanly separates it from the sibling publish_listing. It falls short of 5 only because 'save' doesn't say where the listing is stored, though the 30-minute lifetime implies a server-side draft.
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?
Strong implicit routing: 'Does not contact Vinted' plus 'Any edits require a new draft and renewed confirmation' tells the agent this is the pre-publish staging step and that publish_listing is the follow-up. It never names publish_listing explicitly or states the condition for choosing it, which keeps this below a 5.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.