preview_sticker

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Declares read-only nature and mentions it returns MCP image content from the public CDN. Without annotations, this covers basic safety but misses details like auth or rate limits. Adequate for a simple read operation.

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?

Three sentences with no waste: purpose, usage guidance, and labeling info. Front-loaded with main action.

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?

Complete for the tool's simplicity: explains what it does, how to use parameters, and what output looks like (images labeled). No output schema needed.

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%, baseline 3. Description adds value by explaining the relationship between packageId and stickerId, and mentions default limit. Goes beyond schema.

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 it shows sticker preview images using MCP image content from the public sticker CDN, distinguishing it from siblings like send_sticker (sends) and list_stickers (lists metadata).

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?

Provides clear usage context: give a packageId from list_stickers/search_stickers to preview stickers, or add a stickerId for a single sticker. Mentions labeling for send_sticker. Lacks explicit when-not or alternatives, but context is strong.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.