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

With no annotations, the description carries the safety/behavior burden. It adds valuable context beyond the schema: prerequisite (call get_connected_accounts), return shape (machine summaries plus total_count), and cost (5 tokens). It does not disclose pagination behavior or authorization, but those are less critical for a read-only list operation and are partially covered by schema.

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 four short sentences with the core purpose stated first. Each sentence adds useful information: prerequisite, connection targeting, return shape, and cost. No unnecessary words.

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?

With a 100% schema coverage and an output schema, the description need not explain everything. It covers the key prerequisite (get_connected_accounts), how to target connections, return data shape, and cost, making it complete enough for an agent to invoke correctly.

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 the schema already fully documents all five parameters. The description only reiterates clerk_instance_id's semantics ('target a specific connection, or omit to use default'), which adds no new information beyond the schema's own description. Therefore baseline 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 opens with the verb 'list' and a specific resource ('machines in a connected Clerk instance'), clearly distinguishing this from single-machine tools like clerk.get_machine and mutation tools like clerk.create_machine. The scope ('connected Clerk instance') adds context without ambiguity.

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?

It explicitly instructs to call clerk.get_connected_accounts first and explains how to use clerk_instance_id to target a specific connection or omit it for the default. It does not explicitly state when to avoid this tool or name an alternative (e.g., clerk.get_machine for a single machine), but the usage context is clear.

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