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

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint, establishing the safety profile. The description adds worthwhile behavioral context by disclosing the 1-hour cache and the refresh mechanism, which are not captured in annotations. No contradictions found.

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 two sentences, both dense with value. The first sentence states the core purpose; the second delivers caching and refresh guidance. No filler or 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?

Given the tool has an output schema, it need not describe return values. The description covers what the tool returns (schema components), its caching behavior, and when to refresh. The connection parameter is fully specified in the schema, so the combined picture is complete for a read-only introspection tool.

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 input schema provides detailed descriptions for both parameters (refresh and connection), giving 100% coverage. The tool description only reinforces the refresh parameter in prose without adding new meaning. Per the rubric, baseline 3 is appropriate when schema description coverage is high and the description does not compensate further.

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 uses a specific verb ('Discover') and resource ('full database schema') and enumerates concrete components (tables, columns, types, primary keys, foreign keys, indexes), which clearly distinguishes it from sibling tools like query_sql or analyze_table. The purpose is immediately understandable and 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 description provides a clear usage context: results are cached for 1 hour, and callers should set refresh=true after schema changes. This implies when to use the tool (schema discovery) and gives a practical condition for refreshing, though it does not explicitly state when not to use it or name alternatives.

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