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

Annotations already mark it read-only, idempotent, and open-world, so the description correctly does not repeat those facts; instead it discloses what the tool returns, the non-real-money nature of Manifold probabilities, the payment experience via x402, and the no-data/no-settlement behavior. This adds substantial value beyond the structured metadata and contradicts none of it.

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?

The purpose and return fields are front-loaded in the first sentence, followed only by the two caveats that materially change call behavior (MANA semantics and paid-call settlement) and the HTTP route. No sentence is filler or repeated schema content.

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?

For an optional-parameter, read-only list/search tool with no output schema, the description is complete: it names the returned fields, explains the venue's token/pricing semantics, covers the payment challenge and no-cost-on-no-data behavior, and gives the direct HTTP equivalent. An agent has enough to invoke it correctly without additional documentation.

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 input schema already documents all four parameters with descriptions, examples, and allowed values, so the baseline of 3 applies. The description's 'Search or browse' and output-field list imply the intended use of search/sort/filter but add no parameter-level detail beyond the schema.

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 opening clause 'Search or browse Manifold Markets questions' uses a specific action and resource, and the description lists concrete return fields (probability, outcome type, volume, liquidity, unique bettor count, close time, creator, resolution state). This is distinct enough to separate it from sibling prediction-market tools such as polymarket_markets, even though no sibling is named.

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 provides clear practical guidance: the MANA/play-money caveat, the per-call cost, the unpaid-call challenge behavior, and the fact that a no-data call is never settled and costs nothing. It stops short of explicitly saying when to choose this over prediction_market_search or Polymarket tools, so it gets a 4 rather than a 5.

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