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

Even though no annotations are present, the description compensates well by disclosing key behavioral details: it emits partial and result events, first paint latency (~500ms with is_projected=false and confidence=high), the 2-3s verified result timing, and the vendor_coverage_alert flag when web consensus disagrees. It doesn't cover all potential failure modes or stream teardown behavior, but the core event-driven behavior is clearly disclosed.

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?

The description is compact yet information-dense, covering purpose, transport, event types, timing, confidence semantics, use cases, and a comparative alternative in two sentences. No filler or redundant restatement of the schema. Highly effective front-loading with the STREAMING variant headline.

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 streaming variant with one simple parameter and no output schema, the description fully explains the event contract, latency characteristics, and alternative tool. It tells the agent everything needed to decide between streaming and synchronous calls and interpret the two events. Complete for its complexity class.

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 has 100% coverage for the single required ticker parameter, so the baseline is 3. The description adds contextual meaning beyond the schema by implying the parameter is used to scope the earnings next consensus stream for a specific ticker. While it doesn't elaborate on validation or formatting, the parameter's purpose is obvious from the tool's description.

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 'STREAMING variant of tengu_v3_earnings_next' and states it delivers earnings consensus via Server-Sent Events. It clearly names the two emitted events (partial and result), their semantics, and timing, making the tool's purpose and scope unmistakable. This distinguishes it from its sibling tengu_v3_earnings_next while preserving the shared consensus contract.

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 explicitly states when to use this streaming variant — 'when a consumer can render incrementally and wants the fastest possible first paint' — and specifically cites chat surfaces and live tickers. It also provides a direct exclusion: 'Synchronous consumers should keep using tengu_v3_earnings_next', naming the alternative and explaining the cost-aware tradeoff.

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