explain_postgres

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

Discloses that the query executes to collect real timing, results are discarded, a statement timeout prevents runaway, and write queries are blocked. With no annotations, the description fully covers behavioral traits.

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 main action, followed by execution details, return format, and usage guidance. Every sentence adds value with no wasted words.

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?

The description covers what the tool does, how it works (including execution and timeout), return format, when to use, and what is blocked. With an output schema present (not shown but referenced), the return information is sufficient. All necessary context for an agent to use the tool correctly is provided.

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 already provides detailed parameter descriptions. The tool description adds context like the automatic prepending of EXPLAIN and the 'write queries blocked' constraint, but does not repeat parameter definitions. Given schema coverage appears to be limited (per context signals), the description could have added more direct parameter guidance, but it is adequate.

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?

Clearly states it runs EXPLAIN (ANALYZE, BUFFERS, FORMAT JSON) on a query and returns the plan. Distinguishes from sibling tools like execute_postgres (which runs queries) and describe_postgres_schema (which describes schema).

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?

Explicitly advises using this tool before slow/unfamiliar queries on large tables, and to check describe_postgres_schema first for indexes. Also states write queries are blocked, guiding the agent away from using it for writes.

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