rails_runtime_info

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

Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=false, so the safety profile is covered. The description adds that state is "live" (current, not cached) and enumerates the section categories, but says nothing about cost, latency, or whether introspection has side effects on a running system — and idempotentHint=false is left unexplained.

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?

Three compact clauses: purpose, usage triggers, key params — front-loaded and scannable with zero filler. The trailing "Key params" sentence partially duplicates enum values already in the schema, which is mild waste but keeps the definition self-contained.

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 return-value burden and does so by enumerating the five data categories, and all parameters are documented in the schema. For a read-only introspection tool this is nearly complete; only the meaning of idempotentHint=false and any cost/volume caveats are missing.

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 schema already documents all three parameters and both enums in detail. The description only restates the detail and section enum values and omits the `database` parameter entirely, adding no syntax or semantics beyond structured data. 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?

Opens with a specific noun phrase — "Live runtime state" — and enumerates the concrete resources covered (connection pool, table sizes, pending migrations, cache stats, job queues), so an agent knows exactly what it returns. It implicitly separates itself from static-inspection siblings like rails_get_config or rails_get_schema by the word "Live," but never names a sibling explicitly.

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 "Use when:" clause gives four concrete triggering scenarios (debugging performance, checking database health, verifying deployment state, understanding infrastructure). That is clear positive guidance, but there are no exclusions or named alternatives telling the agent when to prefer rails_diagnose or rails_performance_check instead.

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