Wait for the next lines (fast)

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

With no annotations, the description carries the full burden and does well: it discloses the blocking behavior, the cursor pattern, the timeout fallback, and the to_bot flag on returned lines. It leaves out error behavior and whether the operation is strictly read-only, but the core behavioral model is clear.

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?

Two dense sentences, front-loaded with the return condition and immediately followed by the loop/cursor guidance. No wasted wording.

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 blocking wait tool with no output schema, the description adequately explains what is returned (lines, next, to_bot) and how to continue the loop. It could be more complete about the returned line shape and ordering, but nothing critical for correct invocation 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?

Schema coverage is 100%, so the baseline is 3. The description still adds real meaning beyond the schema by explaining the cursor convention ('pass the returned next as since') and the to_bot marker in results, which the schema alone does not convey.

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 names a specific verb and resource ('Returns as soon as there is a line with seq greater than since') and explains the blocking-wait semantics clearly. It does not explicitly contrast itself with the sibling tail_lines, so an agent must infer the difference from the 'use it in a loop' phrasing.

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 clear usage context: 'Use it in a loop to follow a live room with the least delay: pass the returned next as since.' That tells the agent when this tool is appropriate. It stops short of naming tail_lines as the non-blocking alternative or stating when not to use it.

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