trace_lineage

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

With no annotations provided, the description carries the full burden. It discloses a key behavioral nuance: 'Edges marked model_only mean the SQL could not be parsed down to the column — the dependency is real, the precision is not.' This goes beyond the basic operation and warns about data-quality limitations.

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 compact, front-loaded with the primary purpose, then uses a short usage-rule sentence and a tight Args list. No filler; every sentence and parameter comment serves a purpose.

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?

Despite lack of annotations, the description covers purpose, usage triggers, parameter semantics, and a precision caveat. Since an output schema exists, the absence of return-format details is acceptable. The tool is fully specified for an agent to select and invoke 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 schema has 0% description coverage, but the Args section explains every parameter: table as 'fully qualified or bare', column as optional for table-level lineage, direction with valid values, and depth with a hop range. This adds meaning beyond the bare schema names and defaults.

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 opens with a specific verb and resource: 'Trace where a table or column's data comes from, and what depends on it.' This clearly defines lineage tracing and distinguishes it from sibling tools like search_tables, describe_table, and check_health.

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 gives explicit trigger scenarios: 'when you need to justify a number, when a value looks wrong and you need to find where it was computed, or before suggesting a change to a table so you can say what it would break.' It does not name alternatives directly (e.g., use describe_table for schema-only questions), but the context is clear enough.

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