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

Annotations already declare readOnlyHint=true, and the description reinforces this by citing the GET endpoint. It adds the resolution purpose, which is useful context, but says nothing about pagination behavior, total counts, or result ordering beyond what the schema already lists.

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?

Two compact sentences with zero filler, and the tool's purpose and its relevance to sourceId resolution are both front-loaded. Every clause 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 read-only list tool with full schema coverage and no output schema, the description covers purpose and the underlying endpoint adequately. The only minor gap is that return shape and pagination semantics are left to inference.

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%, so page, pageSize, query, and sortOrder are all fully documented in the schema itself. The description adds no parameter syntax or filtering semantics beyond what the schema provides, so the 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 ('List') and resource ('lead sources'), and the parenthetical adds real meaning: it resolves the sourceId on customer leads, tying it to the related list_customer_leads tool. It stops short of naming sibling tools explicitly, so an agent still has to infer it from context.

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?

No explicit when-to-use or when-not-to-use guidance and no named alternatives. However, 'resolves the sourceId on customer leads' implies the usage context (look up source names when dealing with customer leads), which is enough to be considered implied usage rather than none.

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