get_database_stats

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states the tool retrieves statistics, implying a read-only operation, but doesn't specify if it requires authentication, has rate limits, returns real-time or cached data, or any error conditions. For a tool with zero annotation coverage, this leaves key behavioral traits unclear, scoring a 2.

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 a single, efficient sentence that directly states the tool's purpose and data sources. It's front-loaded with the core action ('Retrieves statistics') and avoids any unnecessary words, making it highly concise and well-structured, earning a 5.

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 tool's complexity (simple read operation with no parameters), no annotations, and no output schema, the description is minimally complete. It explains what the tool does but lacks details on return values, behavioral traits, or usage context. For a tool with no structured support, it's adequate but has clear gaps, scoring a 3.

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 tool has 0 parameters, and schema description coverage is 100% (though empty). The description doesn't need to add parameter details, so it meets the baseline of 4 for tools with no parameters. It appropriately focuses on the tool's purpose without redundant parameter explanations.

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's purpose: 'Retrieves statistics about database activity and the background writer' with specific sources (pg_stat_database and pg_stat_bgwriter). It distinguishes itself from siblings like get_database_connections (which focuses on connections) and list_tables (which lists tables), but doesn't explicitly contrast with all siblings. The verb 'retrieves' and resources 'statistics' are specific, earning a 4.

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 provides no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites, context for usage, or compare with siblings like get_database_connections for connection stats or execute_sql for custom queries. Without any usage context, this is a significant gap, scoring a 2.

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