execute_dml_preview

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

With no annotations, the description carries the behavioral burden and does so well: it clarifies the operation is non-executing (a true dry-run) and specifies what it returns (affected row count plus a sample). It stops short of stating permission requirements or whether any read locks are taken, so it is strong but not exhaustive.

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?

Three tight sentences: purpose, return behavior, and the exclusion/alternative. The key constraint (dry-run, no execution) is front-loaded and nothing is redundant.

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?

With no output schema, the description covers the return values (total affected rows and a sample). It handles the exclusivity constraint and points to the correct alternative, leaving nothing an agent needs in order to call 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?

Only one parameter with 100% schema description coverage, so the schema already documents the sql argument fully. The description reaffirms that it must be a single non-executed UPDATE/DELETE statement but adds nothing beyond the schema's own wording. Baseline 3 is appropriate.

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 (dry-run) and resource (UPDATE/DELETE statements) with scope, and names the sibling tools it is NOT by excluding INSERT/MERGE. An agent can distinguish this from execute_dml and execute_dml_rollback_first without opening any 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?

Explicitly states when to use it (dry-run UPDATE/DELETE), when not to (INSERT and MERGE unsupported), and routes the agent to the correct alternative (execute_dml_rollback_first) for the excluded cases. Both the positive and negative routing are present.

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