list_databases

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

No annotations are provided, so the description must fully disclose behavior. It only states the action without confirming it's read-only, safe, or idempotent. It does not mention whether authentication is needed, rate limits, or any side effects. This leaves an agent uncertain about safety and constraints.

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, complete sentence that efficiently conveys the tool's purpose. It is front-loaded and contains no unnecessary words, earning its place as a concise and well-structured definition.

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?

The tool has a simple function (list databases) and an output schema (existence noted in context), so the description minimally covers functionality. However, it lacks behavioral context such as read-only guarantee, pagination, or error conditions. With no annotations, the description should provide more completeness to fully inform the agent.

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 coverage is 100% (the single parameter 'instance' has a clear schema description: 'Name of the Datasette instance (from config)'). The tool description adds no extra meaning beyond the schema, merely restating the instance context. With full coverage, the baseline is 3, and no additional value is provided.

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 'List all databases in a Datasette instance' clearly states the action (list), the resource (databases), and the scope (a specific instance). It effectively distinguishes from sibling tools like describe_database (specific db), execute_sql (queries), list_instances (instances), and search_table (searches table) by focusing on listing all databases.

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 its siblings. It does not mention prerequisites, limitations, or context such as 'use this before describe_database to discover available databases'. Without such context, an AI agent may not understand the best scenario for invocation.

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