explain_query

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

With no annotations, the description carries the full behavioral burden. It usefully warns that database content is untrusted and should not be treated as instructions, which is real security context. However, it omits key behaviors: it never says whether the plan is estimated or actually executed, that include_actual_plan causes the query to run (side effects/cost), or whether the operation is read-only.

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 tight sentences: the purpose is front-loaded and the security caveat is compact. Nothing is redundant or padded.

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?

There is no output schema, so the description does not need to describe return values, and the parameters are fully covered by the schema. What remains missing for a tool in a crowded performance-analysis family is any guidance on when to choose it over its siblings, which limits completeness.

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 coverage is 100% with all three parameters documented inline, so the baseline of 3 applies. The description adds no syntax, format, or semantics beyond what the schema already states (e.g. it never explains the cost implication of include_actual_plan).

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?

States a specific verb and resource ('Get the execution plan for a SQL query') plus the intent ('to analyze performance'), which is clearly more than a restated name. It does not, however, distinguish itself from near-siblings like analyze_query_performance, get_query_performance, or detect_query_bottlenecks, leaving the agent to guess which performance tool fits.

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?

No when-to-use guidance is given beyond the vague phrase 'to analyze performance'. There are at least four sibling tools in the same performance-analysis space and the description names none of them or any selection condition, so the agent has no routing signal.

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