table_relationships

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 important behavioral context beyond annotations: results are heuristic and based on sampled values, meaning they are not guaranteed exhaustive or exact. This is valuable for setting agent expectations.

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 that states the core concept, defines the heuristic mechanism, and includes the key caveat about sampling. Every part earns its place, and the main idea is front-loaded.

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?

This is a no-parameter, read-only introspection tool with an output schema available. The description adequately explains what the tool computes and how, and nothing else is needed 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?

The tool has zero parameters and the schema is already fully descriptive by being empty, so the baseline of 4 applies. There are no parameter semantics for the description to clarify.

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 clearly defines the tool's output as heuristic foreign-key candidates and specifies the exact heuristic: *_id columns whose sampled values appear in a matching column of another table. It is not a tautology and is readily distinguishable from sibling tools like describe_table or search_columns, though it lacks an explicit verb.

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?

There is no guidance on when to use this tool versus alternatives such as search_columns or describe_table. The description explains what the tool computes but does not state when an agent should prefer it or when a different tool would be more appropriate.

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