Horizon Get Object Lineage

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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds that results span both upstream and downstream dependents, which is useful, but says nothing about behavior when the object doesn't exist, cross-database/account coverage (openWorld), or result volume.

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?

A single front-loaded sentence with no filler. It is efficient but so terse that there is no room for the qualification rules the agent actually needs.

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 values needn't be described. However, for a lineage tool with four parameters and an unenumerated 'direction' argument, the description leaves the agent guessing about valid values and object qualification.

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 coverage is 75%, so baseline is 3. The description's 'upstream source and downstream dependent' is the only hint at what the undocumented 'direction' parameter accepts, but it never states the allowed values (upstream/downstream/both) or that 'both' is the default.

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 and resource ('Retrieve ... object lineage') with explicit scope ('upstream source and downstream dependent'). The word 'object' implicitly separates it from the sibling horizon_get_column_lineage, though that sibling is never named.

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?

No guidance on when to choose this over horizon_get_column_lineage (column-level lineage) or recipes_discover_schema_lineage. No prerequisites stated, and the default 'both' direction is never framed as a choice the agent must consider.

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