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

Annotations already declare destructiveHint=true and idempotentHint=true, so the bar is lower. The description still adds real context beyond them: deletion is permanent and every download link to the file stops working — a concrete downstream consequence an agent can reason about. It does not say what happens on unknown file_id or whether the file is recoverable by an admin.

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 short sentences, front-loaded with the action and the permanence warning. The trailing 'Free.' is an unexplained fragment that adds a billing claim without context, which keeps it from a 5.

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 one-parameter, annotation-rich mutation with no output schema, the description plus annotations cover what an agent needs to call it safely. Minor gaps remain around error behavior and permission requirements, but nothing essential is missing.

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% and the single file_id parameter already carries a description pointing at files_upload's return value. The tool description adds nothing about the parameter, so baseline 3 applies.

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 and resource ('Delete a file') plus a scope qualifier ('for good') that separates it from softer siblings like files_edit or files_remove_storage. An agent knows immediately what this tool does and that it is not a reversible edit.

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 permanence wording implies caution and therefore implies when this is the right call, but the description never names an alternative (files_edit, files_remove_storage) or states preconditions such as ownership or file existence. Usage is inferable rather than stated.

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