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

Annotations already carry readOnlyHint=true, idempotentHint=true, destructiveHint=false, and the description aligns (read-only, does not write). Beyond annotations it adds genuine value: the output is fact-collection not advice/prediction and carries does_not_prove; WorldBank-type sources get retroactively revised so historic-year numbers differ from what was seen before, flagged via pit_notes; subject is fixed to TW_MARKET. The retroactive-revision disclosure is substantial behavioral context. No contradiction with 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?

Front-loaded with the core purpose and organized with ★ bullets, but verbose: the fact that it does not take a ticker is repeated three times ('所以它不收 ticker', '它不收 ticker 因為主體是整個市場', '不收 ticker'). Several lines re-state what the schema and annotations already convey (single optional arg; read-only), adding length without new information.

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?

Thorough for a simple read tool: an output schema exists so return format is covered externally, and the description covers the subject scope (market vs ticker), the honesty wrapper (does_not_prove), the point-in-time revision caveat, preconditions (identified session), and side effects. Only minor gap is as_of semantics, mentioned under parameter scoring.

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 0% so the description carries the burden. It correctly states the only argument is as_of (optional) and that it does not take a ticker. However, it never explains what as_of actually controls (e.g., the point-in-time date for which regime state is read) or any date format semantics. This partial compensation earns a 3, not higher.

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?

States specific verb+resource: reads the 總經 (macro) regime — business cycle signals, rates, yield curve, FX, capital flows. Explicitly distinguishes itself from single-stock tools ('這支講的是整個市場,不是任何一檔個股'), scoping the tool precisely. The example question ('現在景氣循環在哪個位置' is this tool) anchors the purpose concretely.

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?

Gives a clear usage context: use when asking about the market-level business cycle, not about an individual ticker. States it does NOT take a ticker and is not for single-stock questions. Does not explicitly name sibling alternatives like query_regime or positioning_read as the alternative route, so the exclusion is implied rather than named.

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