list_sources

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

Annotations already cover readOnly, idempotent, and destructive hints, so the bar is lower. The description adds useful operational context beyond annotations, including 'not separately rate-limited' and the exact shape of the returned summary (columns, roles, detected join keys). This adds genuine value.

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 compact and front-loaded: purpose, usage context, safety/behavior, and return shape are each covered in a few sentences. 'Advanced tool' is minor garnish, but every substantive sentence earns its place.

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 simple read-only listing tool with two optional parameters and no output schema, the description is complete. It explains what the response contains, including the sources array, per-source fields, and pagination metadata, so an agent can invoke and interpret the result confidently.

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%, with clear descriptions for page and limit. The description does not repeat or extend parameter semantics, which is acceptable because the schema already carries that burden; baseline 3 applies.

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?

States a specific verb and resource ('List all registered data sources for this org') and clarifies it returns schema summaries. It also positions itself as the discovery step before query_data or register_source, which differentiates it from related sibling tools.

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?

Explicitly tells the agent when to use the tool: 'Use this to discover available tables before calling query_data or register_source.' It provides clear usage context but does not explicitly state when not to use it or name alternatives such as get_source_schema.

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