Get server info

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

Annotations already provide readOnlyHint=true. The description adds valuable behavioral details: handling of effective_wal_level for PG 18 vs 19+, and that divergence indicates pending reload. This goes beyond annotations and clarifies edge cases.

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?

Single sentence, efficiently structured, front-loaded with the main action. Every clause adds necessary detail 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?

With no parameters and an output schema (assumed), the description completely covers what the tool returns, including version-specific nuance. No gaps remain for the agent.

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?

No parameters exist, so schema coverage is 100%. The description does not need to add parameter info, but it does explain what the return values include. Baseline for zero parameters is 4, which 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 'Return the MCPg server version, access mode, transport, database connection status, and PostgreSQL wal_level / effective_wal_level'. This uses a specific verb and defines the resource exactly. No sibling tool offers the same output, so differentiation is clear.

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?

Although not explicitly stating when to use or not, the tool's unique purpose among siblings (none other returns server info) makes it obvious. The description implies it is the go-to for server metadata. Slight deduction for lack of explicit alternatives or exclusions.

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