Weekend trading: one market's history across weekends

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

Annotations already cover the safe-read (readOnlyHint) and open-world profile, and the description adds real value beyond them: newest-first ordering, symbol auto-resolution behavior, and ISO timestamp twins. It stops short of describing pagination or row limits, but the added behavioral context is substantive.

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?

Three tight sentences with the core computation front-loaded, followed by scoping caveats and output notes. Dense but every sentence carries weight; 'ISO twins' is jargon but is the only slightly opaque phrasing.

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?

With no output schema, the description carries the return-format burden and does so reasonably: pct and dollar values per tracked weekend, newest first, timestamps as ISO pairs. A short note on pagination or empty-result handling would round it out, but nothing essential for correct invocation is missing.

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 100%, so baseline is 3, but the description adds meaning the schema omits: the symbol-resolution rule ('TSLA' -> 'xyz:TSLA') and which symbols are valid. The `fields` parameter is covered by its own schema description rather than by the prose.

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?

Names a specific verb+resource+computation: one HIP-3 TradFi market's Friday-close -> Sunday-close move (pct and dollar) across every tracked weekend. This distinguishes it from siblings like flowscan_weekend_weeks (all markets) and flowscan_weekend_prices (price series), so an agent can route without opening schemas.

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?

Clearly states applicability constraints: only DEX-prefixed TradFi markets have data, bare symbols are auto-resolved ('TSLA' -> 'xyz:TSLA'), and crypto like 'BTC' yields nothing. Strong when-to-use context, but it never names an alternative sibling tool to use instead for crypto or non-weekend data.

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