fkIndexCoverage

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

Annotations already mark the tool as read-only, idempotent, and non-destructive. The description adds the specific output behavior (only returns uncovF FKs, includes suggested index columns), which is useful beyond annotations. It does not mention edge cases or side effects, but for a read-only audit tool this is adequate.

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 the core purpose first and the alternative second. No redundant wording, every sentence contributes meaning.

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?

An output schema exists, so return-value details are covered. The description explains behavior, output filtering, and an alternative tool. The only notable gap is the undocumented schema parameter, which prevents a perfect score.

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%, with table and connection documented in the schema but the schema parameter is undocumented. The tool description adds no additional parameter semantics beyond the schema, leaving the schema parameter ambiguous. A score of 3 reflects the adequate but not complete parameter guidance.

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 states a specific audit task (child-side foreign keys), the precise filter (FKs not covered by an index starting with FK columns in order), and the output (suggested index columns). It also distinguishes itself from describeTable by noting what describeTable is for, making its purpose unambiguous relative to at least one sibling.

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?

It gives an explicit alternative ('use describeTable to inspect all keys and indexes of one table') and a usage condition for the table parameter ('Omit to scan the schema'). It does not enumerate when-not conditions for other sibling tools like redundantIndexes, but the context for when to use this tool is clear.

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