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

Annotations already establish read-only, idempotent, non-destructive behavior, so the bar is lower. The description adds useful behavioral context by revealing the full scope of the response and the optional inclusion of recent trades, which helps set agent expectations beyond the annotations.

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 description is a single, front-loaded sentence that lists exactly what the agent will get, with no filler or repetition. Every item in the enumeration earns its place by clarifying the tool's output.

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 burden of explaining return contents, and it does so comprehensively: markets, outcome names/prices, token ids, tick size, min order size, rules, resolution, and status. Combined with rich annotations and clear schema descriptions, nothing essential is missing for correct invocation.

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. The description reinforces the 'slug' lookup and 'recent trades' inclusion, but it does not add meaningful parameter semantics beyond what the input schema already documents.

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 clearly identifies the resource ('Full event by slug') and enumerates its contents, distinguishing it from market-query tools like get_orderbook or get_price_history. The title 'Get one event' reinforces the singular retrieval purpose.

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 schema's slug description tells the agent to source the slug from search_markets, giving clear prerequisite context. The description signals the right time to use the tool (when full event detail is needed), though it never explicitly states when not to use it or names alternatives.

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