list_sources

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

The annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false. The description adds non-obvious behavioral context by stating 'This does not call the Sugra API,' indicating a local, low-cost operation beyond what the annotations convey.

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 three short sentences with no filler. It front-loads the core purpose, then gives a practical usage hint, then a clarifying behavioral note. Every 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?

The tool is simple: zero parameters, an output schema is present, and annotations cover safety and idempotency. The description adds the only missing context (localiveness and how to use the result), making it complete for correct invocation.

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 tool has zero parameters, so the baseline is 4. The description doesn't attempt to explain parameters because none exist; instead it focuses on the meaning of the returned family names, which is relevant downstream.

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 a specific verb and resource: 'List source families in the bundled catalog with endpoint counts.' It clearly distinguishes this from siblings like search_endpoints or list_toolsets by naming the exact object being listed and the data returned.

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?

It provides actionable guidance: 'Use the family names as the source filter on search_endpoints.' It also clarifies that this tool does not call the Sugra API, indicating when it is appropriate for local/bundled data. It gives clear context but doesn't spell out explicit exclusion scenarios.

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