list_rules

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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds domain semantics about rule kinds, but says nothing about result size, pagination, or how the catalog is scoped.

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 short sentences, front-loaded with what is listed and what comes back. The rule-kind sentence is compact and meaningful rather than filler.

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 covering return shape, annotations covering safety, and full parameter documentation in the schema, the description supplies enough for an agent to call it correctly. Only the absence of sibling routing keeps it from full marks.

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% and the single engine parameter is already documented as "mssql or pg; empty lists both". The description adds no filtering detail beyond the schema, so 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 specific verb and resource ("List the Lens rule catalog (health checks)") and enumerates returned fields (ID, engine, category, severity, title). It distinguishes itself from action-oriented siblings like check/explain_rule only implicitly through the noun "catalog"; no sibling is named.

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?

Usage is implied: this is the enumeration endpoint, and the note that "series" rules judge recordings while others run in a check hints at downstream workflow. It never says when to use this instead of explain_rule or get_finding, and gives no prerequisites or exclusions.

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