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

Annotations already declare readOnlyHint and openWorldHint, so safety is covered by structured data. The description adds that the endpoint is public and that prices/sizes are normalized to numbers, which is useful context, but it says nothing about rate limits, auth, snapshot staleness, or pagination depth.

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 no waste. Scope and data-shape come first, then the sibling routing, all front-loaded.

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?

An output schema exists, so return values need not be described, and safety is covered by annotations. The description covers scope, the ID-type caveat, and sibling routing, which is sufficient for a simple single-parameter fetch, though it omits any note on snapshot freshness or batching limits.

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 a single parameter at 100% schema coverage the baseline is 3, but the description adds real meaning: it clarifies that token_id refers to a Polymarket CLOB outcome token and explicitly contrasts it with a Gamma market id, preventing a plausible ID-confusion error.

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 ('Fetch a public CLOB order-book snapshot') and scopes it to exactly one outcome token_id. It also preempts a likely confusion by noting that an outcome token differs from a Gamma market id, so an agent can distinguish this from market-level siblings.

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?

Explicitly routes to alternatives: polymarket_tokens_orderbooks for batching several books and polymarket_token_price for a side-specific quote. The condition selecting each alternative is stated, leaving nothing to inference.

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