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

Annotations cover safety (readOnly, non-destructive, openWorld), and the description adds substantial value beyond them: the ~5 min in-market refresh cadence, the meaning of the ext:true late flag, and the full auth model (Coil Live subscription with 7-day trial, connector sign-in, or x402 pay-per-call). It explicitly discloses failure behavior: without subscription or wallet it returns a PaymentRequired object and no data.

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?

Front-loaded with the resource and its contents, then the caveats (state map not ranking, auth/payment). It is dense and jargon-heavy, but nearly every clause (refresh rate, ext flag, payment fallback) carries operational meaning, so little is wasted.

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 0 params and no output schema, the description compensates by naming the fields surfaced on the board and the refresh behavior, and it warns of the PaymentRequired fallback. It stops short of describing the shape of the returned object, but for a read-only board tool with no schema this is close to complete.

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?

Zero parameters, so there is nothing to disambiguate and the baseline is 4. The description correctly implies a no-argument read and adds no misleading parameter claims.

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 verb and resource (get the live day-trade board) and enumerates exactly what the board contains: 18-cell lights grid, GO, FUEL vs anchor ETF, efficiency, ATR%, vs-SPY, entry-window, ROOM on ~70 names. It also draws a clear conceptual boundary ('A STATE MAP, not a ranking') and identifies itself as the 'Live intraday version', which distinguishes it from the non-live get_day_board sibling.

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 'Live intraday version' framing plus the ~5 min refresh window tells the agent when this is appropriate versus a static/as-of board. However, it never explicitly names an alternative (e.g., get_day_board or get_board_asof) or states a when-not condition, so routing is implied rather than spelled out.

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