explain_query

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

No annotations are provided, so the description carries the burden. It discloses the most important behavioral trait: the query is not executed, only explained. It also states the output is a JSON plan and limits input to SELECT/WITH queries, which is meaningful behavioral context.

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?

One compact sentence conveys the action, the output format, the non-execution guarantee, and the accepted query type. There is no filler or redundant restating of the tool name.

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 one-parameter tool with an output schema available, the description is complete: it states what input is accepted, what behavior to expect (EXPLAIN only), and what output is returned. No critical information is missing for correct invocation.

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 0%, so the description must compensate. It does by identifying the single parameter as a SELECT/WITH query for which the plan is returned. This gives the parameter functional meaning beyond the bare schema type 'string'.

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 uses a specific verb ('Return') and a concrete resource ('JSON query plan'), and explicitly notes 'EXPLAIN, no execution' for 'SELECT/WITH' queries. This clearly distinguishes the tool from schema/table inspection siblings like describe_table or list_tables.

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 clear context: use this to get an EXPLAIN plan without executing the query, and it is scoped to SELECT/WITH queries. It does not explicitly name alternative tools or exclusions, but the sibling set is different enough that the intended use is reasonably clear.

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