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

Annotations already indicate this is a write operation (readOnlyHint false). The description adds that the slug is auto-generated from the name and that color/sprite apply only when no custom icon image is set. This provides useful behavioral context beyond the annotations, so a 4.

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 concise (three short sentences) and front-loads the core action. However, it begins with 'Create Source' which repeats the title, slightly reducing efficiency. Still, it's well-structured and not verbose, so a 4.

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?

Given the simple create operation, an output schema exists, and the schema provides full parameter details, the description covers the key behavioral aspects (slug generation, conditional styling). It doesn't mention error handling or idempotency, but those are not essential for a basic create. A 4 is appropriate.

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 schema covers 100% of parameters with detailed descriptions, so the baseline is 3. The description adds that the slug is derived from the name and clarifies the conditional application of color and sprite, which enriches parameter understanding. Thus a 4.

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 'Create a review source' with a specific verb and resource, and notes that the slug is generated from the name. It clearly indicates a creation operation but does not explicitly differentiate from sibling tools like updateSource. The verb 'create' is unambiguous given the sibling list, so it earns a 4.

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 provides no explicit guidance on when to use this tool versus alternatives. It implies creation via the verb, but doesn't mention that updateSource should be used for modifying existing sources, or any exclusions. This is implied usage, so a 3.

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