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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is covered. The description adds real value by disclosing the mechanism (EXPLAIN plus safety analysis) and warning that destructive-looking DDL such as DROP FUNCTION/TRIGGER/VIEW/PROCEDURE is accepted and analyzed without being applied.

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?

Two tight sentences, front-loaded with the core purpose and then the supported statement classes. The DDL enumeration is somewhat long but earns its place by clarifying that DROP-type statements are in scope for preview.

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?

For a two-parameter tool with no output schema and a read-only annotation profile, the description covers purpose, mechanism, and accepted inputs. The only shortfall is that it doesn't hint at what the preview returns (plan output vs. safety warnings), which would help an agent interpret results.

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% with only two required parameters (sql, dbSourceId), both documented in the schema itself. The description adds no parameter-level syntax, dialect, or format guidance, so the baseline 3 applies.

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 combination (dry-run a SQL query) and clarifies the mechanism with EXPLAIN + safety analysis, plus the statement classes it accepts. It implicitly distinguishes itself from nexusai_db_query_execute via 'preview/dry-run' but never names that sibling, so sibling differentiation is left to inference.

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?

'Dry-run' implies the pre-execution use case, but the description never states when to reach for this versus nexusai_db_query_execute, nor any prerequisites such as the query needing to be valid or the source being reachable. Usage is inferable but not spelled out.

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