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

The description uses 'Fetch' and 'Mirrors GET', which strongly implies a read-only operation with no side effects. However, since no annotations are provided, the description carries the burden, and it does not explicitly mention error behavior, permissions, or lack of mutation. Overall it is fairly transparent but not exhaustive.

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—two sentences—and front-loads the core action. Every word adds value: the resource, the scope, the return payload, and a useful API reference. No filler or redundancy.

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 fetch tool with a single parameter, the description covers the essential context: what is fetched, what is included in the response, and how the parameter is interpreted. It does not need to explain return schemas or error codes for this level of complexity.

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 parameter description goes beyond the schema's type string by explaining the two possible formats (slug for library rows, UUID for user rows) and provides a concrete example. This gives the agent clear, actionable guidance for constructing valid calls.

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 action ('Fetch') and the resource ('a single template'), and specifies that it returns the full DSL source and sampleData. The phrase 'library or caller-owned' and the focal 'by ID' effectively distinguish it from list_templates, making the purpose unambiguous.

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 usage for retrieving a specific template by ID, but it does not explicitly state when to prefer this over alternatives. It references the REST endpoint but provides no direct guidance on when not to use it or when to use list_templates instead. This leaves some room for interpretation.

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