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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the description isn't carrying the safety burden alone; it still adds the workflow requirement to confirm with the user before calling, which annotations cannot express. 'Irreversible' is consistent with destructiveHint and deletion remaining idempotent, so there's no contradiction, though it says nothing about downstream effects on posts referencing the file.

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?

Two short sentences: the action and scope come first, the uid source and the irreversibility warning follow. Nothing is wasted and nothing important is buried.

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 two-parameter destructive tool with full annotations and no output schema, the definition covers the action, the identifier source, and the safety precondition. Only the collateral impact (e.g. whether posts using the media are affected) is left unstated.

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 schema already documents that media_uid comes from list_media and that workspace_uid may be omitted for the default workspace. The description repeats the uid provenance but adds no meaning beyond the schema, so the baseline of 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?

The description gives a precise verb-plus-resource ('Permanently delete a file from the media library') and names the sibling list_media as the source of the uid. It doesn't explicitly contrast itself with delete_post or delete_workspace, so sibling differentiation is only implicit in the resource noun.

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?

'Irreversible — confirm with the user first' establishes a required precondition for use, and '(uid from list_media)' routes the agent to the tool that supplies the identifier. There's no when-not guidance, but the usage context is clear enough for an agent to act on.

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