explain

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states the tool explains query plans and helps optimize queries, but doesn't describe what the output looks like (e.g., textual explanation, structured data), whether it's read-only or has side effects, or any constraints like file access permissions or rate limits. For a tool with no annotations, this is a significant gap.

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?

The description is concise and front-loaded, consisting of two sentences that directly state the purpose and benefit. There's no wasted verbiage, and it efficiently communicates the core functionality. However, it could be slightly improved by integrating usage guidance more seamlessly.

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 the complexity of SQL query analysis and the lack of annotations and output schema, the description is incomplete. It doesn't explain the return format, potential errors, or behavioral traits, leaving gaps for an agent to understand how to interpret results. For a tool with no structured output and no annotations, more descriptive context is needed.

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?

The input schema has 100% description coverage, with clear documentation for both parameters ('db' as path to file, 'sql' as SQL query). The description adds no additional parameter semantics beyond what the schema provides, such as format details or examples. With high schema coverage, the baseline score of 3 is appropriate as the schema handles the heavy lifting.

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 the tool's purpose: 'Explain the query plan for a SQL query (EXPLAIN QUERY PLAN).' It specifies the verb ('explain') and resource ('query plan'), and adds the helpful context 'Helps optimize queries.' However, it doesn't explicitly differentiate from sibling tools like 'query' or 'schema,' which could handle similar SQL-related tasks.

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 provides no guidance on when to use this tool versus alternatives. It mentions 'Helps optimize queries,' which implies usage for performance tuning, but doesn't specify scenarios, prerequisites, or exclusions compared to siblings like 'query' or 'schema.' This lack of explicit when/when-not guidance limits its utility for an agent.

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