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

Annotations already declare destructiveHint=true, idempotentHint=true, and readOnly=false, so the safety profile is covered. The description adds the partial-update semantic ('Only provided fields change') and mirrors PATCH /api/v1/media/{media}, which is genuinely useful, but it does not explain what is destructive (e.g. tag clearing) or any auth/permission 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?

Two tight sentences: purpose and field scope first, then the update semantic and the underlying endpoint. Every clause carries information with no padding.

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 mutation tool with no output schema, the annotations plus 100% param coverage plus the PATCH mirror leave little missing. It could mention effects on dependent resources or permission requirements, but an agent has enough to call it 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 documents each field including the null-to-clear behavior and max lengths. The description only restates the field grouping as audio tags, adding little beyond what the schema provides — the 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?

States a specific verb and resource ('Update a media file's metadata') and enumerates the editable fields (name plus audio tags). This implicitly separates it from siblings like update_tag and update_stream, though it never names those alternatives explicitly.

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?

No when-to-use guidance, no prerequisites, and no routing to or away from the many sibling update_* tools. The only usable cue is 'Only provided fields change', which clarifies the update mode but not when to choose this tool.

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