event_list

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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so safety is covered. The description adds behavioral context: 'newest first', 'paginated', and the fields each item contains (time, severity, type, module, user, machine, message). This goes beyond annotations without contradicting them.

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 compact sentences. The purpose and scope are front-loaded, and the item-field list is a useful detail packed efficiently. No filler or repetition; every sentence adds value.

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 read-only, paginated list tool with fully documented parameters and no output schema, the description covers everything an agent needs: what it returns (item fields), ordering, filtering, and a use case. It is complete 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 description coverage is 100%, so all four parameters (limit, offset, target, severity) are already documented with types and defaults. The description only adds the notion of optional severity filtering, which is also in the schema. It provides no extra semantics beyond what the schema conveys, so baseline 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?

States a specific verb and resource ('List Horizon audit events') with clear scope (newest first, optional severity filter). The READ prefix reinforces read-only intent, and the use case ('what went wrong recently') makes it distinguishable from sibling tools like session_list or health_summary.

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?

Provides a clear use case: 'Use for "what went wrong recently"'. It does not explicitly name alternatives or exclusions, but the audit-event focus implicitly separates it from other list tools. The guidance is adequate for an agent to know when to invoke it.

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