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

No annotations are provided, so the description carries the burden. It discloses that the operation is 'Sensitive', returns token metadata for active credentials, notes cost, and states that JWT-format tokens are not listed. This adds meaningful safety and scope context beyond the schema, though it does not mention read-only nature or behavior around expired/revoked defaults (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 compact and front-loaded, starting with the purpose. Every sentence contributes: purpose, sensitivity warning, prerequisite, instance targeting, return summary, and cost. No filler or repetition.

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 high schema coverage (100%) and presence of an output schema, the description only needs to cover the operation flow and key caveats. It successfully includes prerequisite (connected accounts), instance selection, a sensitivity note, cost, and a return-value summary. No important context appears missing for an agent to select and invoke the tool 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 coverage is 100%, with all six parameters described in the input schema. The description adds only minimal value by reinforcing clerk_instance_id usage ('omit to use the default account') and noting JWT tokens are not returned, but it does not add substantive detail beyond what the schema already provides.

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 'List M2M tokens for a machine in a connected Clerk instance,' which is a specific verb+resource+scope. It clearly differentiates from sibling list tools like list_machines or list_users by targeting M2M tokens for a machine and explicitly notes JWT-format tokens are excluded.

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 provides explicit usage context by instructing to call clerk.get_connected_accounts first and explaining how to use clerk_instance_id for targeting a connection or omit it for default. It also mentions a limitation (JWT-format tokens not listed) but does not explicitly name alternatives or state when not to use the tool, so it falls short of full guidance.

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