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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the description only needs to add context. It adds that the tool returns 'review source metadata' scoped to 'project reviews,' which is mildly informative but does not disclose deeper behaviors beyond what annotations already cover.

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 short and front-loaded with the key action. The only minor inefficiency is that the first line repeats the tool name/title ('List Sources'), but the rest is direct and free of unnecessary detail.

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 zero-parameter, read-only list tool with an output schema and strong annotations, the description is largely complete. It states the resource and scope, though it does not explicitly mention whether the list is unfiltered or how many sources it returns, which could be slightly more explicit.

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 and schema description coverage is 100%, so there are no parameter semantics required. The description correctly avoids inventing parameters and just states what the listing returns.

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 ('Retrieve') with a clear resource ('review source metadata'), and the scope is narrowed to what is 'available for project reviews.' This clearly differentiates it from sibling source tools like createSource, updateSource, and deleteSource.

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 implies this tool is for read-only listing of review sources, and the sibling names make the distinction obvious. However, it does not explicitly state when to prefer this tool over alternatives or provide any 'do not use when' guidance, leaving usage partially implied.

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