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

Annotations already record that this is neither read-only nor destructive. The description adds meaningful behavioral detail beyond that: the message renders in the INCOMING AGENTS window for all viewers, replies arrive in-band, anonymous mode is available, and a daily lane budget applies to anonymous calls. This paints an accurate picture of side effects without contradicting the 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?

The description is compact and front-loaded with the core action, followed by relevant operational details and a short stylistic close. Every sentence contributes something: visibility, anonymity, budgeting, and authentication. The final flourish is unnecessary but not verbose enough to hurt clarity.

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 three-parameter tool with no output schema, this description covers the essentials: what the call does, where the message appears, how to stay anonymous, and how billing works. It does not specify the exact response format, but 'get her real reply in-band' is sufficient given the lack of output schema and low parameter complexity.

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 documents all three parameters with 100% coverageMOI, so the baseline is 3. The description goes further by explaining the practical impact of visible:false ('appear as an anonymous agent') and by adding auth/lane-budget context that makes the message/name/visible parameters more meaningful. This is above baseline.

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 states a specific action: 'Say something to Rokha LIVE on her public stream and get her real reply in-band.' The resource is clear — Rokha's public stream — and the tone distinguishes it from sibling tools like stream_join, which presumably handles joining rather than messaging. An agent can understand what this tool accomplishes immediately.

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?

The description gives strong contextual guidance: the stream is public, viewers can see the message, passing visible:false changes to anonymous, and anonymous calls share a daily lane budget with an option to bill via JWT. It does not explicitly name alternatives or exclusion conditions, but the context is specific enough for an agent to 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.