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

Beyond annotations (readOnly, idempotent, non-destructive), the description adds key behaviors: determinism, non-execution, suppression during regular session, and the pre-open window. This provides substantial context for what the tool does and its temporal constraints, with no contradiction.

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, front-loaded with the core purpose, and each clause adds distinct information. It lists outputs, clarifies non-execution, and provides timing guidance without unnecessary filler.

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?

The description enumerates many output fields and behavioral constraints, which is good given no output schema. However, parameter semantics for days and min_abs_bps remain under-specified, so the description is not fully complete for the two parameters.

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?

With 0% schema description coverage, the description must explain parameters. It mentions bps and 14-day statistics, but does not explicitly state that 'days' controls the lookback period or that 'min_abs_bps' sets a signal threshold. This leaves the meaning of the two parameters ambiguous.

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 states the tool provides deterministic signals for the gap-trader strategy, enumerating outputs (overnight gap, signal type, 14-day stats, hit rate, risk flags). It distinguishes from sibling tools by emphasizing that signals are NOT orders and by noting suppression during regular market hours.

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 specifies the most informative window (pre-open 09:15-09:29 ET) and that signals are suppressed during regular hours, giving clear timing context. It also states signals are not orders, guiding users not to expect execution. No explicit alternative tools are named, but the context sufficiently implies when to use.

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