index_usage

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

The description only says 'Show', implying a read-only operation, but with no annotations it carries the full burden of behavioral disclosure. It does not state what metrics are returned, whether statistics are cumulative or reset, or if any special permissions are needed. This is too thin for an agent to understand the tool's behavior beyond the name.

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 sentence with no fluff, front-loaded with the action and purpose. Every word contributes to the definition, making it efficient and easy to parse.

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 and no annotations, the description should explain what the returned statistics look like or how to interpret 'unused' indexes. The phrase 'index usage statistics' is ambiguous about the actual metric names, and there is no guidance on how the output maps to the tool's purpose. This leaves an agent uncertain about what to do with the results.

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?

The schema provides 100% coverage for the single parameter 'table' with the description 'Filter for a specific table (optional)'. The description adds no additional parameter detail, but since the schema fully documents it, the baseline score of 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?

The description uses a specific verb ('Show') and resource ('index usage statistics') with a clear objective ('to identify unused or rarely used indexes'). This clearly differentiates it from siblings like list_indexes or table_stats, which serve different purposes. The purpose is unmistakable.

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 phrase 'to identify unused or rarely used indexes' provides a concrete use case, telling the agent when this tool is appropriate. It does not explicitly mention alternatives or when not to use it, but the context is clear enough for a single-purpose diagnostic tool.

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