test_connection

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

With no annotations, the description must carry the behavioral burden, and it does disclose the observable outcome (version, current DB, user, read-only status, latency) plus the read-only transaction angle, which signals a non-mutating probe. It stops short of explicitly stating there are no side effects or what a failure response looks like, so it is strong but not exhaustive.

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?

Front-loads the purpose, then returns, then usage recommendation, then the parameter default — a sensible ordering with no filler. It is slightly longer than strictly necessary because the return list and the parameter default are stated in separate clauses, but nothing is wasted.

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 and no annotations, so the description must explain both purpose and returns, which it does by listing the five returned values. Usage context and the default-instance rule are also covered, leaving only failure/error semantics unspecified for a simple connectivity probe.

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 100%, and the single optional 'instance' parameter is fully documented in the schema (name, default, available value demo). The description only restates the default-instance behavior, adding no new syntax or format detail beyond the schema. Baseline 3 applies when the schema does the work.

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 (test GaussDB data source connectivity) and enumerates the concrete return contents: server version, current database, user, read-only status, and latency. This is unmistakably distinct from the schema/query-oriented siblings (describe_table, execute_select, list_schemas, list_tables), which do not probe connectivity.

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?

Gives clear when-to-use context: run at session start or before other tool calls to confirm reachability and read-only transaction enforcement, and use it to diagnose connection, credential, or timeout problems. It also resolves the no-instance case. There is no explicit when-not-to-use or named alternative, but no sibling overlaps in function, so the guidance is effectively complete.

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