List Available Stickers

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

Annotations already indicate readOnlyHint=true. The description adds behavioral context by specifying that it lists *every* sticker, the included fields, and that results should be used to know which moods can be expressed. No contradiction with annotations.

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 with no redundancy: the first sentence states the tool's purpose, the second gives usage context. Front-loaded and efficient.

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?

For a zero-parameter, read-only listing tool, the description fully specifies what is listed, when to call it, and how it feeds into subsequent actions. No output schema exists, but the description mentions the key output fields, making it 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?

The tool has zero parameters, so the schema fully covers parameter semantics (baseline 4). The description adds value by explaining what data is returned and how it relates to sending stickers, though no parameter-specific info is needed.

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 uses the verb 'List' with a specific resource ('every sticker in the library') and names the output fields ('id, name and emotion/scene tags'), clearly stating the action and result. It distinguishes from siblings like send_sticker, which sends, and add_sticker, which adds.

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 gives explicit when-to-use guidance: 'Call this once early in a conversation (or when send_sticker reports no match)' and then instructs 'afterwards you can call send_sticker directly'. This also clarifies the alternative tool.

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