list_tables

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It clearly describes a read-only listing operation and discloses that row counts are 'estimated', which signals approximate values. However, it does not explicitly state that the tool is non-destructive or requires no special permissions. Still, the term 'list' implies a safe read operation, and the 'estimated' caveat adds useful behavioral nuance, meriting a score above baseline.

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 concise sentence that front-loads the core purpose ('List all tables, views, and schemas') and immediately follows with the key output details ('estimated row counts and table sizes'). Every word earns its place, with no redundancy or filler.

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 low complexity, lack of output schema, and no annotations, the description is fairly complete: it states what the tool lists and what accompanying data is returned. The only minor gap is a slight ambiguity over the phrase 'and schemas' (whether schemas are listed as separate objects or just included as context), but this is a small omission in an otherwise adequate description.

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 already provides 100% description coverage for both parameters: 'schema' (Database schema name, default public) and 'include_views' (Whether to include database views, default true). The tool description does not add any additional meaning beyond the schema, so the baseline score of 3 applies. No enrichment of parameter semantics is present.

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 the specific verb 'List' and clearly identifies the resource: 'all tables, views, and schemas in the PostgreSQL database'. It also specifies additional output details ('estimated row counts and table sizes'), which distinguishes it from sibling tools like describe_table (which describes a single table) and get_db_stats (which focuses on database stats). This leaves no ambiguity about the tool's function.

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 does not mention that describe_table is more appropriate for inspecting a specific table, or that get_db_stats is useful for broader database statistics. There is no explicit when-to-use or when-not-to-use context, so the agent is left to infer usage solely from the tool name.

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