get_index_stats

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

Annotations already indicate read-only, non-destructive, and idempotent behavior, but the description adds valuable context by specifying the exclusion of system tables and detailing the types of metrics returned (e.g., cardinality, size, efficiency). This enhances transparency beyond what annotations provide, though it doesn't cover aspects like rate limits or authentication needs.

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 well-structured and front-loaded, starting with the core purpose, followed by bullet points of returns and helps, and ending with a critical note. Every sentence adds value without redundancy, 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?

Given the tool's complexity and the absence of an output schema, the description does a good job of outlining what metrics are returned and what issues it helps identify. However, it could be more complete by briefly mentioning the format of the output or any limitations, though the annotations and schema coverage mitigate this gap.

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?

With 100% schema description coverage, the input schema fully documents all three parameters, including their types, descriptions, and enums for 'order_by.' The description does not add any parameter-specific details beyond what the schema provides, so it meets the baseline score of 3.

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 explicitly states the action ('Get detailed index statistics') and the target ('for MySQL user tables'), clearly distinguishing it from sibling tools like 'get_table_stats' or 'find_unused_indexes' by focusing specifically on index-level metrics rather than table-level statistics or unused index detection.

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 description provides clear context by specifying that it 'only analyzes user/custom tables and excludes MySQL system tables,' which helps guide when to use it. However, it does not explicitly mention when to choose this tool over alternatives like 'find_unused_indexes' or 'get_index_recommendations,' which are related sibling tools.

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