Send Sticker

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

The description discloses the random-selection behavior and stickerId override, but it directly contradicts the readOnlyHint=true annotation by describing a 'send' operation, which is an action with side effects. This is a clear annotation contradiction, so the score is 1.

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 compact yet comprehensive, front-loading the purpose and then giving usage notes. Every sentence adds practical value without redundancy.

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 with two well-documented parameters, and an output schema exists. The description covers preparation (listing stickers), selection strategy, and fallback behavior, making it adequately complete for an agent to use correctly.

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?

The schema already covers both parameters with descriptions. The description adds value by explaining how to pick query based on conversation mood, and the behavior when multiple stickers match. This goes beyond the schema, so a score of 4 is appropriate.

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 'Send an expressive sticker (meme/表情包) that renders as an image in the chat' — a specific verb and resource. It also distinguishes itself from siblings like list_available_stickers and add_sticker by focusing on sending in chat.

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?

It explicitly says 'Use this proactively whenever a sticker would make the reply more fun or expressive' and provides examples of when to use. It also instructs to call list_available_stickers first if the library hasn't been seen, giving clear guidance.

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