send_sticker

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

No annotations provided, but the description covers behavioral traits: stickers appear rendered in conversation, not as file attachment; error conditions for uninstalled pack or invalid sticker_id; and required steps to ensure pack is installed.

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?

Four sentences, each earning its place. Front-loaded with main purpose, then details on nature, errors, and alternatives. No fluff.

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?

Covers usage, prerequisites, error conditions, and alternatives. Lacks explicit return value (no output schema), but error handling is described. Overall fairly complete for a direct message tool.

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%, but the description adds meaning: explains pack_id is a hex string from list_sticker_packs, sticker_id is 0-based integer, and relates to other tools for pack management.

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 the action: 'Send a single sticker to a Signal contact in a direct message.' It specifies the resource (sticker) and mode (DM), and distinguishes from siblings like send_group_sticker and send_attachment.

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 explicit when-to-use (expressive reaction/decoration), when-not (use send_attachment for images, send_group_sticker for groups), and prerequisites (pack must be installed, recommended to use list_sticker_packs first).

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