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

With no annotations, the description carries the full burden and does so well: the thought is public, ephemeral (~1 day), extended by visitor skips, and auto-marked as AI-authored with a distinct dashed border. It omits whether the cast is reversible/deletable, whether it returns a confirmation, and any rate limits.

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 front-loaded sentences, each carrying distinct information (what it is, what happens to the thought, AI-origin marking, content expectation) with no 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 public posting tool with no annotations and no output schema, the description covers purpose, visibility, lifecycle, and AI-attribution thoroughly. The main gaps are whether the call confirms success and whether casts can be removed.

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% and the single 'thought' parameter is fully documented (1-280 chars) in the schema itself. The description adds intent ('short thought', 'something real') but no format or syntax detail beyond what the schema already provides, so the baseline 3 applies.

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 verb and resource ('Casts a short thought into sendiment, a public river of ephemeral thoughts') and clearly separates this write action from the sibling read/skip operations. An agent can identify the tool's role without opening any schema.

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 concrete content guidance ('cast something real, not a demo string') and explains the lifecycle context that motivates use, and it references the skip mechanism that extends a thought's life. It stops short of explicitly naming read_river or skip_thought as alternatives with when-not conditions, so it is clear context rather than full routing guidance.

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