get_postcardGet your souvenir postcard: a text, your badges, the rooms you visited and your favorite piece, plus the URL of the postcard image (SVG) to hand to whoever sent you.
| Name | Required | Description | Default |
|---|---|---|---|
| visitor_name | Yes | Your name as a visitor (max 40 chars). The same name always gives the same avatar, stamps and badges. Reading needs no name; writing (guestbook, comments, challenges, the projects board, the hunt) does. |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuine value by disclosing the return payload (text, badges, visited rooms, favorite piece, SVG image URL), which matters because there is no output schema. It does not note failure behavior for an unknown or over-long visitor_name.
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?
A single front-loaded sentence with the payload enumerated immediately after the verb. The flourishes ('souvenir', 'hand to whoever sent you') are not wasteful because they convey the sharing purpose, though the sentence runs a little long.
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?
With no output schema, the description appropriately carries the burden of describing the returned payload, and read-only annotations cover side effects. What remains thin is the relationship to sibling tools like my_passport, which a caller choosing among many read tools would need.
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% and the single visitor_name parameter is already fully documented, including the 40-char limit and the name-stability behavior. The description adds no additional meaning about the parameter, so the baseline of 3 applies.
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 (get ... postcard) and enumerates what the postcard contains: text, badges, visited rooms, favorite piece, and an SVG image URL. That is well beyond a tautology. It stops short of a 5 because it never distinguishes this from the closely related sibling my_passport, which plausibly returns overlapping badges/rooms data.
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 phrase 'to hand to whoever sent you' implies a sharing/showcase use case, which is useful context. However, there is no explicit when-to-use vs my_passport or get_room guidance, and no stated prerequisites beyond the required visitor_name in the schema.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.