List tables

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

Annotations already declare the safety profile (readOnly, idempotent, non-destructive, closed-world), so the bar is lower. The description adds value by disclosing what is returned, notably that row counts are approximate and sizes are in MB, which an agent cannot infer from structured fields alone. It stops short of covering pagination or result-limit behavior on large databases.

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?

Two tight sentences: the first front-loads what the tool returns, the second covers routing and narrowing. No filler, and the most load-bearing information (scope plus alternatives) leads.

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 output schema, the description carries the burden of describing return values and does so field by field. Combined with the sibling routing and parameter narrowing advice, an agent has everything needed to select and invoke this tool 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?

Schema description coverage is 100%, including the non-obvious semantics of name_pattern (substring match without %, add % for prefix/suffix). The description only echoes 'narrow with schema and name_pattern' and adds no syntax beyond the schema, so the baseline 3 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?

Opens with a specific verb and resource ('Lists user tables') and enumerates the exact return fields (schema, approximate row count, data/index size in MB, creation/modification dates). It also explicitly distinguishes itself from find_columns and get_table_schema, so an agent can disambiguate without opening a schema.

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?

Gives concrete when-to-use cases ('find tables by name or schema', 'spot the large ones') and routes to alternatives by naming both find_columns (column-based lookup) and get_table_schema (single-table details) with their selecting conditions. The closing hint about narrowing with schema and name_pattern is actionable guidance.

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