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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, openWorld), so the bar is lower. The description adds genuinely useful non-annotation context: the shape of the returned data and the 'Pro' tier hint. It stops short of stating auth/key requirements or session-boundary caveats, which keeps it below a 5.

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: payload definition first, then the use-case question, then the tier flag. Every clause earns its place and nothing is repeated from the schema.

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 correctly names the three returned components, and the annotations cover safety. It is complete enough to call correctly, though it omits the Pro/auth prerequisite detail and any note on what 'latest' resolves to.

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% with both parameters fully described (top_n default 25, session date or 'latest'). The description only loosely ties to these via 'top net-premium tickers' and 'for a session', adding no format or constraint detail beyond the schema. Baseline 3 applies.

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 a specific subject and payload: signed large-order net-premium into calls vs puts, the intraday cumulative curve, and top tickers per session. The 'market-wide' scope cleanly distinguishes it from the sector-level sibling sector_tide, so an agent can route without opening either schema.

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 an explicit trigger question ('is options flow bullish or bearish overall today?') and flags 'Pro', implying tier gating. It stops short of naming the alternative (sector_tide) for narrowing to a sector or an exclusion case, so it is clear context rather than full when/when-not guidance.

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