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

Annotations cover the safety profile (idempotentHint=true, destructiveHint=false, readOnlyHint=false), and the description adds substantial behavior beyond them: idempotency is on the PAIR not the direction, existingDirection reports same/opposite, warnings explain suppressed chips and cycles, placedInColumn reports the column used, and the column-choice fallback chain (first output link column → first link column → pinned edge with warning) is fully disclosed.

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?

Eight sentences is long, but each carries distinct load-bearing information (idempotency semantics, direction, column placement, warning cases) and the core action and pair-idempotency rule are front-loaded. Slightly dense, but minimal waste.

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?

No output schema exists, yet the description explains the meaningful return signals (existingDirection, warning, placedInColumn) and every edge case that affects whether a chip becomes visible. For a 6-parameter mutation tool, an agent has everything needed to call it and interpret the result.

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 100% so the baseline is 3, but the description adds real meaning for toColumnIndex (defaults to the row's first OUTPUT link column, falls back to first link column, can be overridden) that the schema only restates more briefly. It does not extend meaning for baseRevision or the four required IDs beyond what the schema already documents.

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+resource (create a trace link) and immediately scopes it: between two TraceIDs, resolved server-side within one project, addressed by the TraceID pair. It also names the sibling that performs the inverse operation (traceable_link_delete), so the agent can partition the create/delete pair without opening either 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?

Gives clear conditions: use this to add an edge, use traceable_link_delete to remove one, and it explains what happens when an edge already exists in either direction (nothing is written, existing edge returned). It does not explicitly state when to prefer this over other write tools in the family, but the create/delete routing is explicit.

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