Post an AI card on stream

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

Beyond the annotations (readOnlyHint=false, destructiveHint=false), the description reveals that the card renders with preconfigured styling (not controlled by the caller), that a prerequisite is that the AI Card alert type must be enabled, and that a specific error (card_disabled) occurs if not. It also notes that the AI Card type is OFF by default, which is valuable behavioral context.

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 three sentences long, front-loaded with the core purpose, then includes usage guidance and an important error condition. Every sentence adds value with no redundancy or filler.

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 simple tool with two parameters and no output schema, the description covers what the tool does, how to use it, when to use it, and a common failure mode. It is complete enough for an agent to select and invoke the tool correctly without needing additional context.

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 input schema already fully describes both parameters (title and message) with detailed meaning, so schema coverage is 100%. The description adds only a high-level note that 'You supply only the text,' which does not materially enhance the parameter-specific understanding already provided by the 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 specifies the action ('Post a card onto the live stream via DualStream's alert system'), the target (AI Card alert type), and the rendered outcome (both canvases with streamer-configured styling, position, sound, duration). It distinguishes this from sibling tools like trigger_clip by focusing on the card alert type and the fact that the user only supplies text.

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?

Explicit usage guidance is provided: 'Use for short, timely, viewer-facing moments' and 'only when the user asked for it or set up an automation.' This sets both positive contexts and a clear restriction. It also explains the card_disabled error and how to resolve it, which helps the agent decide when this tool is appropriate.

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