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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, so safety is covered. The description adds useful nuance that rows carry both a canonical state and a derived stage, including the stage deadline, which is not in annotations or the input schema. It says nothing about pagination behavior or rate limits.

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 core purpose is stated first, followed by one dense sentence about row contents and a short concrete example. No filler, though the example line adds modest value for an eleven-parameter tool.

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 eleven optional filters, an output schema and rich annotations, the definition is workable but leaves gaps: no default paging note (pageSize 20, max 100), no explanation of the cursor-only-applies-to-`new` constraint at tool level, and no routing versus sibling market-listing tools.

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 73% and the schema documents most parameters well (sort, cursor, search, creator, pricingModel, sourceTokenId). The description adds essentially no parameter semantics beyond implying state/category/chain filtering through the example, so the baseline of 3 is appropriate.

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?

"List prediction markets on Kellian" gives a specific verb and resource, and the second sentence explains the shape of each row (marketState, lifecycleStage, stageDeadline). It does not, however, distinguish this from close siblings like kellian_list_pending_resolution_markets or kellian_list_related_markets, which also list markets.

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?

The example "List live CRYPTO markets on Base" implies a usage pattern, and the note to prefer lifecycleStage tells the agent how to interpret results. But there is no explicit when-to-use/when-not guidance versus siblings such as get_market (single fetch) or list_related_markets.

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