Chat Say

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

With no annotations present, the description carries the behavioral load and does it well: it spells out platform-dependent reply threading (Twitch/Kick threaded vs '@name' on YouTube) and the three refusal conditions (over-length, duplicate line within 30 s, venue rate-limiting). That is real operational context an agent cannot get from the bare schema. It stops short of 5 because it never states what a successful post looks like operationally (e.g. what the null venue/who defaults resolve to) or what happens to the line after posting.

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?

Front-loaded with the action, then trigger conditions, then parameter semantics, then failure modes — a sensible ordering with no filler sentences. The middle is slightly dense and run-on (the reply_to parenthetical spans two platform behaviors in one breath), but nothing is redundant.

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 an unannotated 4-parameter mutation tool this covers the essentials: when to call it, what each parameter does, and the concrete refusal cases. The output schema is present so return values need not be described. The remaining gap is the meaning of null defaults for venue and who, which an agent may need to reason about before omitting them.

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 description coverage is 0%, so all meaning must come from the prose, and it delivers: reply_to is explained as a chat line's number with per-platform rendering, venue is explained in both forms ('<name>' for one venue, 'all' for every reading venue), and who is described as the role logged with the line. Every one of the four parameters gets semantics beyond its bare JSON type.

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 first sentence gives a concrete verb and resource ("Say one line in chat") and the following clause frames the intent (reply to a viewer, answer someone, greet the room), so an agent can picture the action immediately. It is not explicitly contrasted with near-siblings like phone_say or stage_say, but "in chat" plus the venue/reply_to discussion makes the target channel 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?

"Reach for it when you reply to a viewer, answer someone in chat, or greet the room" is an explicit positive trigger set rather than an implied one. There are no exclusion rules or named alternatives (e.g. when to use chat_read first to find a line number), which keeps it short of a 5.

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