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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety and reach are known. The description adds only the 'one record by ticker' scoping; it does not mention rate limits, auth needs, or what the resource contains beyond the ticker lookup.

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, front-loaded with the primary action and followed by routing. No filler or redundancy; every clause earns its place.

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 a single-record fetch, the essentials are covered: what it returns (a series record), the key (series ticker), and where to go for discovery or events. An output schema exists, so return-value detail need not be restated, and annotations cover the safety profile.

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% with a single documented series_ticker parameter, so the schema carries the load. The description's 'by series ticker' reinforces that the parameter is the unique identifier, but adds no format or syntax 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?

States a specific verb and resource ('Fetch one Kalshi series record') with explicit cardinality ('one') and the lookup key ('by series ticker'). It clearly separates itself from the sibling setter kalshi_series and the event-browsing tools.

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?

Explicitly routes the agent: use kalshi_series to discover series and kalshi_events to browse their events, marking this tool as the single-record retrieval. The when-to-use-this vs alternatives guidance is fully spelled out.

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