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

Annotations already cover read-only/idempotent/openWorld, and the description adds real value beyond them: the four-state resolution lifecycle (not proposed / proposed in challenge window / disputed / resolved), verbatim resolution rules with a named source, and the multi-outcome sum-to-100¢ check. It does not mention auth scoping or rate limits, so it is not a full behavioral profile.

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 trigger, then the return payload, then the optional-parameter guidance. The return enumeration is dense but every item (fees, rules verbatim, resolution status) is a distinct capability rather than padding; it is slightly long but not wasteful.

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 full burden of describing returns, and it does so thoroughly: prices with bid/ask/spread, 1h/24h/7d/30d change plus 30-day range, volume/liquidity, taker fees, rules, and live resolution status. An agent has everything needed to call it and interpret the result.

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%, so the baseline is 3, but the description adds meaning the schema doesn't carry: 'add outcome to drill into one' explains the conditional purpose of the optional parameter, and the multi-outcome behavior (lists every outcome, checks that prices sum to 100¢) tells the agent why it might set it.

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 a specific verb+resource ('one Polymarket market or event') and enumerates exactly what it reports: price, resolution rules, proposal/dispute status, end time, fees, and price movement. The scoping word 'one' implicitly distinguishes it from sibling aggregations like pm_moves and pm_leaderboard, so an agent can route without opening the 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?

It states a clear triggering condition ('Use this when the user asks about one Polymarket market or event') and routes the agent to pm_search as the source of slugs, plus tells it to add 'outcome' to drill into a single leg of a multi-outcome event. It stops short of an explicit when-not-to-use clause (e.g. 'do not use for a portfolio of markets'), so it is strong but not fully exhaustive.

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