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

Annotations already flag openWorld, non-readOnly and non-idempotent. The description adds genuinely useful behavior beyond that: throughput (~1 MB/s), the 50 MB cap, and the return value (assetId) with how to reference it (image_N/video_N/audio_N). No auth/permission details, but strong coverage.

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 sentences, all content load-bearing: formats, size/rate limits, and return value. Front-loaded with the action and source, no filler.

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?

With no output schema, the description correctly supplies the return contract (assetId and its downstream use), plus format, size and timing constraints. Nothing needed to call it correctly appears to be 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 description coverage is 100%, so both 'url' and 'email' are already documented. The description adds context on how the returned assetId is consumed but no extra meaning for the input parameters themselves, 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+resource (upload an asset) and the source mechanism (a public https URL), plus the exact media types accepted. An agent can distinguish this from siblings like muse_generate_image or muse_write_file without opening the 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?

The 'from a public https URL' constraint and the media-type list implicitly define the usage context, but there is no explicit when-to-use-vs-alternatives routing (e.g., versus muse_write_file or muse_generate_image). 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.