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

Annotations only give readOnlyHint=false/destructiveHint=false, and the description adds substantial context beyond that: the raw key is returned exactly once, it must not be re-shown in chat, an owner/admin permission is required, and the return fields (key_id, key_prefix) that feed revocation. This is exactly the kind of non-obvious behavior an agent needs.

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?

Three sentences, front-loaded with the core action, then the security constraint, then the follow-up and reference link. No filler, and the most consequential warning (returned once, don't repeat) is positioned prominently.

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 2-param mutation with no output schema, the description compensates by naming the returned fields, the revocation path, the permission requirement, and a docs URL. An agent has everything needed to invoke it correctly and safely.

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% for both parameters, so the schema already documents worker_id and label fully; the description only restates the ownership constraint already in the schema note. Baseline 3 is appropriate when the schema carries the parameter burden.

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?

States a specific verb+resource: mint a `tng_` bearer key for a worker to call Tango's HTTP worker API. It names the API methods the key enables (pull_task, update_task, complete_task) and clearly separates itself from revoke_worker_api_key and the register/rotate siblings.

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?

Gives a clear when-to-use context — issuing a key so a worker runs outside MCP — plus the ownership precondition and the explicit follow-up tool for revocation (revoke_worker_api_key with key_id or key_prefix). It does not contrast itself against the adjacent register_worker_key/rotate_worker_key siblings, which is the only gap.

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