Analyze MPP query plan

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

Annotations declare readOnlyHint=true, openWorldHint=false. The description adds value by confirming no writes/DDL, detailing the safety pre-flight, and explaining the output (slice count, motion nodes, metadata). It also discloses the vanilla PG behavior. No contradictions with annotations.

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, front-loaded with the core action, and organized into clear sentences. It ends with a relevant example. Every sentence contributes value without 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 the complexity of MPP query plan analysis, the description covers key outputs (slice count, motion types, metadata), safety constraints, and availability. The presence of an output schema (context) reduces the need to detail return fields. Minor gap: edge cases or error handling not addressed.

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 50% (database param documented, sql param not). The description adds meaning for 'sql' via its purpose and example, but does not detail the database parameter beyond what the schema provides. This partially compensates; 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?

The description clearly states the tool runs EXPLAIN (ANALYZE, FORMAT JSON) on SQL and rolls up MPP-specific facts like slice count and motion nodes. It differentiates itself from sibling analyze_query_plan by referencing the same safety pre-flight, and specifies behavior on vanilla PG (returns available=false). This provides a specific verb+resource and distinguishes from siblings effectively.

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 indicates that writes/DDL are rejected (when not to use) and that the tool is MPP-specific (vanilla PG returns false). It gives an example and mentions the safety pre-flight analogy to analyze_query_plan(io=True). However, it does not explicitly contrast with other plan analysis tools or state prerequisites (e.g., MPP extension), which would improve guidance.

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