list_sources

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

Beyond the annotations (readOnlyHint, idempotentHint, destructiveHint), the description adds valuable context: it explicitly states 'Read-only and non-destructive; not separately rate-limited,' and describes the return shape including the sources array with id, name, and schema summary fields. This goes beyond what annotations provide and gives the agent a complete behavioral picture.

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 and front-loaded with the core purpose, followed by usage guidance, alternatives, safety, and return format. The opening 'Advanced tool.' is slightly redundant but does not detract. Each sentence earns its place, and the structure flows logically.

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 list tool with two documented parameters and no output schema, the description is complete: it explains scope, usage, alternatives, safety, and return format. It does not cover error conditions or authentication, but these are likely handled elsewhere. The description provides enough for an agent to call 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?

Schema description coverage is 100% for both parameters (page and limit), and the schema already describes their defaults and limits. The tool description does not add additional semantic meaning beyond the schema, so a baseline of 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 lists all registered data sources for the org with schema summaries, using a specific verb and resource. It explicitly differentiates from siblings like register_source, get_source_schema, and list_data, making its purpose unambiguous.

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 explicitly says when to use it: 'Use this to discover available tables before calling query_data or register_source.' It also names alternatives for other tasks: 'Use register_source to add a source, get_source_schema for one source's full profile, and list_data to browse the connect_data store instead.' This provides clear when-to and when-not-to guidance.

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