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

Annotations already mark this as read-only and non-destructive. The description adds meaningful behavioral context: it aggregates sources from both the organization and the client, returns curated view keys, and implies the views are usable only through query_context_source. It does not mention output structure or edge cases, but given the annotations, this is solid.

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?

Three concise, purposeful sentences: the first states the core scope, the second explains the output's key use, and the third gives the when-to-use trigger. No filler or repetition of schema/annotation data.

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 covers what is returned (sources and curated views), how the return is used (view keys for query_context_source), and when to invoke it. The only meaningful gap is the parameter-selection ambiguity, but that is already reflected in parameter_semantics.

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 only 50%: client has a short description, but client_id only has format/pattern with no semantic explanation. The tool description never addresses how to choose between client and client_id, whether either is sufficient, or what each resolves to. Since coverage is low, the description needed to compensate and did not.

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 states a specific verb ('List') and a distinct resource: external data sources connected to a client, including the organization's sources plus the client's own. It also clarifies that the tool exposes curated views with keys for query_context_source, which clearly separates it from the sibling query_context_source and get_client_context 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 it: 'when the shared brief is not enough and the answer likely lives in the agency's own systems.' It also points to the related query_context_source tool for the next step. It stops short of enumerating when-not-to-use cases or naming all alternative tools, so it earns a 4 rather than a 5.

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