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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is fully covered structurally. The description adds genuinely new behavioral facts beyond that: a free-tier truncation at three markets per board, two paid access paths (key or x402 endpoint), and an explicit 'information only, not financial advice' disclaimer. It stops short of describing response shape, board count, or pagination.

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?

It leads with the scope claim, then the per-market field list, then the access/paywall rule, then the disclaimer — a sensible front-loaded order with no filler sentences. Density is high and some tokens ('$', 'GT line', 'tagged holders') are opaque shorthand that spend space without conveying meaning to a fresh agent.

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 burden of telling the agent what comes back, and it does list the per-market fields plus the free-vs-paid truncation rule. Gaps remain around whether one board equals one game, how many boards exist, and whether results are paginated — but for a zero-parameter read tool this is close to sufficient.

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 takes zero parameters, so there is nothing for the description to disambiguate and the baseline of 4 applies. The text does implicitly clarify scope by bounding the board to Polymarket games and US midterm races only.

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 names the resource specifically — a market board covering Polymarket games and US midterm races — and enumerates what each entry contains (sides, price, $, wallets, tagged holders, GT line, Smart-money line), which is far more than a restatement of the name. It does not explicitly contrast itself with siblings like market_heat or pm_edges, so the boundary is inferred rather than stated.

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?

There is no statement of when to call this versus pm_edges, pm_smart_money_entries, market_heat, or line_check_board. The only conditional information is commercial (top 3 per board free; a paid key or x402 returns everything), which tells the agent about access cost but not about task selection.

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