indexStats

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

Annotations already declare readOnlyHint=true, destructiveHint=false, and idempotentHint=true, so the safety profile is covered. The description adds context about the nature of the returned data (live counters) but does not describe pagination, empty-result behavior, or permission requirements. Given the annotation coverage, a 3 is appropriate – it adds some value but not extensive behavioral detail.

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 with zero redundancy: the first states the core purpose and scope, the second provides the key alternative. The most important information (what it does and its scope) is front-loaded, and every word 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 read-only inspection tool with an output schema present, the description covers the essential use case and scope (table or schema), and explicitly points to the alternative when live stats are not needed. It omits any mention of performance implications or result size, but these are not critical for a tool of this type, and the annotations cover safety. The definition is sufficiently complete for an agent to invoke it correctly.

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 67% (connection and table have descriptions, schema does not). The description clarifies that table is optional ('Omit to scan the schema') and that the tool works for 'one table or a schema', giving meaning to the schema parameter beyond the schema field. However, it does not explicitly document the schema parameter's format or interplay with table, so the compensation is partial. Baseline 3 is fair.

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 ('Inspect'), a clear resource ('index definitions'), and the precise data returned (operational size, usage, cardinality counters) for a table or schema. It explicitly differentiates itself from describeTable by contrasting 'live index statistics' with structural metadata, so an agent can distinguish it from a sibling without opening schemas.

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?

Gives explicit when-to-use context (inspecting index stats) and names describeTable as the alternative for structural metadata without live stats. It does not address other index-focused siblings like unusedIndexes or redundantIndexes, but the primary differentiation is clear and the usage scenario is unambiguous.

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