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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds meaningful context beyond that: the data is 'credential-free public market-data JSON' and is 'normalized,' telling the agent no authentication is needed and the output is pre-processed.

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 what-it-does clause is front-loaded, followed by the two key parameter notes and the alternative pointer. Every sentence carries information, though the parameter restatements slightly duplicate the schema.

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 an output schema present, return values need not be explained, and annotations cover the safety profile. The description supplies purpose, key parameter behavior, and an alternative, leaving only pagination/limits unstated, which is a minor gap for this 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 description coverage is 100%, so the schema already documents all six parameters. The description restates event_ticker and series_ticker behavior (defaulting from the event ticker) but adds no syntax, format, or constraint detail beyond what the schema provides. Baseline 3 applies.

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 precise verb and resource: 'Returns normalized Kalshi candlesticks grouped by market for one event.' The scope ('for one event,' 'grouped by market') is clear enough to separate it from a single-market call, though it does not explicitly distinguish itself from close siblings like kalshi_markets_history or kalshi_historical_market_history.

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 names one alternative, kalshi_market_history, but gives no explicit condition for choosing between them beyond the implicit 'event vs market' framing. The routing hint is present but the when-not/when-exactly guidance is left to inference.

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