explainQuery

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

With no annotations, description discloses engine-dependent output format and non-execution behavior. Could add that non-SELECT statements may fail.

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 sentences, front-loaded with purpose, no redundancy.

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?

Given single parameter, no output schema, and sibling context, description covers purpose, constraints, and output behavior completely.

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 already has 100% coverage with a clear description. Description reinforces that it must be SELECT and returns plan without execution, adding value.

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 clearly states it returns the estimated execution plan for a SELECT SQL query without execution, distinguishing it from sibling tools like `query` (executes) and `describeTable` (describes structure).

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?

Mentions it's for SELECT queries and does not execute, implying planning context. However, lacks explicit when-not or alternatives like `query` for execution.

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