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

With no annotations at all, the description carries the full burden and does disclose useful behavior beyond the schema: that the identifier may be a slug, id, or URL, and that an event slug fans out to all its markets. It omits failure behavior (invalid slug, missing market) and any rate-limit or caching notes, which is the remaining gap for an unannotated tool.

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?

Two sentences, both of which earn their place: the first front-loads the resource and the payload, the second delivers the identifier flexibility, the event-slug caveat, and the usage cue. No filler or restatement of the tool name.

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 enumerating return fields is somewhat redundant, but the description adds the non-obvious bits an agent needs: identifier formats, event-slug fan-out, and when to reach for it. The unexplained `depth` parameter and absent error behavior are the only meaningful omissions for a 2-parameter read tool.

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 0%, so the description must compensate. It does well for `market`, spelling out the three accepted identifier forms and the event-slug aggregation. But `depth` (default 5) is never explained — the phrase 'order book (top bids and asks)' only hints at truncation and never ties it to the depth parameter, leaving one of two parameters effectively undocumented.

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 ('One Polymarket market by slug, id or URL') and enumerates exactly what comes back (question, rules, probabilities, bid/ask, order book). It never names its closest siblings polymarket_search or polymarket_top_markets, so the agent gets no explicit differentiation, but the scope is unambiguous on its own.

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?

'Use before placing a trade or to quote exact odds' gives a real usage context, which is better than nothing. However, with three sibling tools in the same family (polymarket_search, polymarket_top_markets, prediction_markets_search), the description offers no when-not or alternative routing — an agent holding a keyword rather than a slug still has to guess which tool to call.

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