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

With no annotations, the description carries the burden of behavioral disclosure. It explicitly mentions the required Authorization header for Pro components and indicates the output is full TypeScript source. It lacks details on error handling or rate limits, but for a simple read tool the key behaviors are covered.

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 two sentences, front-loaded with the action and resource, then a concise note on authentication. Every sentence contributes useful information with no fluff.

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 has only one parameter, no output schema, and no annotations. The description, combined with the schema, fully conveys the tool's purpose, what it returns (source code), and an important access requirement. There is no significant missing context for an agent to invoke it successfully.

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 input schema already has 100% coverage of the single 'name' parameter with a clear example and pointer to search_registry. The tool description adds no additional parameter semantics beyond what the schema provides, so a baseline score of 3 is appropriate.

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 clearly states the tool fetches the full TypeScript source of a Crucible component, using the specific verb 'Fetch' and naming the resource. This differentiates it from siblings like get_usage (which likely provides usage docs) and install_instructions, as it is explicitly about obtaining source code.

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 gives a clear use case ('ready to drop into a shadcn-style project') and notes an authentication prerequisite for Pro components, providing enough context for when to use this tool. However, it does not explicitly contrast with sibling tools or state when not to use it, so it stops short of a 5.

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