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 states 'Read-only,' mentions audit logging ('Every call is written to the audit ledger'), and explains that 'tables the policy denies are absent rather than marked.' These are valuable side-effect and security behaviors beyond basic operation.

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 concise (three sentences) and front-loaded with the core purpose. Each sentence adds value: purpose, usage guidance, return format, and behavioral notes. No fluff or redundancy, making it highly efficient.

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 there is no output schema, the description explicitly explains the return format ('one entry per table with its connector, schema-qualified name and description') and the denial behavior. It covers usage and side effects adequately for a simple list operation, though it omits error handling or pagination details, which slightly reduces completeness.

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 single parameter 'connector' is fully described in the schema (100% coverage) as 'Connector name (optional, defaults to all).' The description adds no additional parameter meaning; it only mentions connector as part of the output structure. Since schema coverage is high, 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?

The description clearly states the tool's purpose: 'List the database tables this gateway is allowed to expose.' It uses a specific verb (list) and resource (database tables), and explicitly distinguishes itself from siblings like describe_table and query by noting it provides the authoritative list of reachable tables. This is a model of purpose clarity.

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 explicit guidance: 'Call it before describe_table or query when the table names are not already known.' This tells the agent when to use it (before others when names unknown), but does not explicitly state when not to use it or mention alternative tools. It implies usage context but falls short of full when/when-not coverage.

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