trace_data_flow

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), so the bar is low. The description still adds real semantics not in annotations: it walks call/import edges rather than values through variables, and returns ordered steps rather than an unordered set. It does not describe pagination or clipping behavior beyond the schema's own hints.

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?

Four short sentences, front-loaded with the action and result, then scope exclusion, then the alternative-tool routing rule. Only minor filler ('Give a focal, a direction and a depth') repeats what the schema enforces.

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?

There is no output schema, but the description compensates by stating the return shape ('the whole path back, as ordered steps'). With 100% schema coverage and full annotations, the agent has enough to invoke correctly; only edge-case behavior (clipping, response truncation) is left to the schema.

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 100% across all 9 parameters, so the schema already carries the meaning of focal, direction, depth, target, and the char/limit aliases. The description only restates focal/direction/depth without adding format or interaction detail. Baseline 3 applies when the schema does the heavy lifting.

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?

Specific verb+resource: 'Walk the call chain out from ONE entity and get the whole path back, as ordered steps', with the traversal direction made explicit. It also differentiates itself from a named sibling ('Naming TWO things? Use trace_path'), so an agent can route between the two without opening a schema.

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 states the required inputs ('Give a focal, a direction and a depth'), names the alternative tool and the condition that selects it (two named entities -> trace_path), and excludes value-flow tracing. That is clear positive and negative guidance, though no other siblings (impact_analysis, graph_neighborhood) are addressed.

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