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

With no annotations, the description carries the burden of behavioral disclosure. It reveals that data is delayed, decays in minutes, and is not suitable as a trading input—critical context. It lacks explicit detail on output format or edge cases but provides strong caveats that go beyond a simple summary.

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 dense but effectively front-loaded with the core purpose ('Yesterday's day-trade state map'). It packs a lot of detail into a compact space, though some acronyms (GO, FUEL, ROOM) are unexplained, slightly reducing clarity.

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?

Given no output schema or annotations and moderate complexity, the description covers the content, staleness, and live alternative. It could be more complete by defining key terms (e.g., ROOM) or outlining the exact response shape, but the description provides enough context for an agent to decide whether to invoke it and what to expect.

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 tool has zero parameters and the schema is empty, so there is no parameter burden. The description appropriately focuses on the output and limitations rather than parameter details, aligning with the baseline for parameterless tools.

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 clearly states what the tool provides: a 'Yesterday's day-trade state map' with a specific grid of indicators (price/RSI/MACD, 5m-1D) and trading states (GO, FUEL, ROOM) across ~70 liquid names. It distinguishes itself from the live sibling by explicitly labeling the live version as a separate tool.

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 explicitly says the free delayed tier is a 'schema/shape preview, not a trading input' and mentions that day states decay in minutes, implying use the live sibling when actual trading decisions are needed. It also names the live alternative directly, giving clear usage guidance.

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