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

The description discloses a lot beyond the annotations: the file's contents (not its name) are inspected, invalid files are refused AND removed, and passing here is not equivalent to being releasable. However, 'the file is removed' describes a destructive outcome while destructiveHint=false, creating a tension an agent cannot resolve from the structured fields alone.

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 dense sentences, no filler, and the core action and the failure behavior are front-loaded before the forward reference to check_readiness.

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 mutating tool with no output schema, the description covers failure modes, side effects (removal), and the post-condition boundary versus check_readiness. It leaves unstated the success side effect (what the file is attached to) and the origin of upload_id, minor gaps given the annotation coverage.

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 67% (name and artist are documented; upload_id is not). The description does add a genuine disambiguation — 'the file itself, not its name' — clarifying that upload_id refers to file content rather than the optional name parameter, but it never says where upload_id comes from (presumably request_upload). Baseline 3 given partial schema coverage plus one useful clarification.

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?

Specific verb+resource: it validates an uploaded file against the upload spec and attaches it only on success. It also actively distinguishes itself from the sibling check_readiness ('Passing here is not the same as being releasable'), so an agent can route correctly without opening either schema.

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 clear when-not conditions (non-MP3 master, non-square or sub-3000px cover → refused) and names the alternative tool (check_readiness) for the releasability question. It does not explicitly name request_upload as the required predecessor or state the ordering, which keeps it short of a 5.

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