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

With no annotations provided, the description carries the full behavioral burden. It discloses that the thought is public, drifts down the screen, sinks after roughly a day unless skipped, is marked as AI-origin, and rendered with a dashed border. These are significant behavioral traits that an agent could not infer from the schema alone.

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: the core action, the lifecycle, the AI provenance marking, and the experimental context with a usage exhortation. The most important information is front-loaded and there is no 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?

For a tool with a single parameter, no output schema, and no siblings, the description covers everything needed to invoke it correctly: destination, public visibility, ephemerality, AI labeling, and appropriate content. No critical behavioral or usage detail is missing.

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 documents the sole parameter 'thought' with a clear description and length constraints, so baseline is 3. The tool description adds qualitative guidance—'short thought' and 'not a demo string'—which enriches the expected meaning beyond the schema's technical definition.

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 opens with a specific verb and resource: 'Casts a short thought into sendiment'. It clearly identifies the public river and what the action accomplishes. There are no sibling tools to differentiate, but the purpose is unambiguous.

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 explicit usage context: this is for casting real AI-authored thoughts into a public experiment, and it explicitly warns 'cast something real, not a demo string'. This tells the agent both when to use it and what kind of input is appropriate, effectively covering when-not as well.

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