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

Annotations already establish this as a read-only, idempotent operation. The description adds meaningful behavioral specifics: it enumerates the full queryable schema, includes rules, and discloses what is deliberately not exposed. It does not mention response format or pagination, but those are minor for a parameterless schema tool.

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 entire description is one front-loaded sentence that conveys scope, association with run_sql, and inclusion of rules/exclusions with no wasted words.

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?

For a parameterless schema-discovery tool, the description is complete: it states what is returned, the governing rules, and the deliberate exclusions. Combined with rich annotations, an agent has everything needed to 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 has zero parameters, so there is nothing for the description to document. The schema already fully covers the empty parameter set, and the description appropriately focuses on output scope instead.

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 ('List') and a precise resource ('every relation and column queryable via run_sql'), and further clarifies it includes rules and deliberate exclusions. This clearly distinguishes it from sibling data-retrieval tools by tying it directly to run_sql.

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 makes it clear that this tool is the schema reference for run_sql, so an agent can infer when to use it. However, it does not explicitly name alternative metadata tools or state when not to use it, leaving a small gap in routing guidance.

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