db_describe_schema

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

With no annotations, the description carries the burden of behavioral disclosure. It reveals that results are cached to avoid repeated database calls, a useful trait. However, it does not explicitly confirm read-only behavior, mention any permissions required, or describe potential side effects (though likely none). It adds some context but not comprehensive coverage.

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 three sentences, each earning its place: what it returns, when to use it, and a note about caching. It is front-loaded with the core purpose and contains no filler or redundant information.

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?

This is a simple, parameterless tool. The description conveys the return value ('tables and views with column count'), usage context ('use this first'), and a behavioral nuance (caching). Given the lack of output schema and no parameters, this is complete for an agent to select and invoke it correctly.

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 takes zero parameters, and the input schema is empty. Per the rubric, 0 params earns a baseline of 4. The description appropriately avoids inventing parameter details and focuses on behavior.

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 starts with a specific verb+resource: 'Returns all available tables and views with their column count.' This clearly differentiates it from siblings like db_list_databases (databases only) and db_describe_table (a single table), making its purpose unambiguous.

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 phrase 'Use this first to understand what data is available before writing queries' gives explicit when-to-use context. It implies this tool precedes query-writing tools but does not explicitly name alternatives or exclusions, so it falls just short of a 5.

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