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

Annotations already declare the write profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false); the description adds the non-obvious fact that the media is *copied* into project storage rather than referenced by URL, plus an input-source restriction that functions as a hard failure mode. It does not cover duplicate handling, size/format limits, or processing latency, which matter given idempotentHint=false.

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 clauses: the action/scope first, the restriction second. No filler, no restating of the title, and every sentence carries distinct information.

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 3-parameter write with no output schema, the description covers what is copied, from where, and what is rejected — enough to call it correctly. The remaining gap is what comes back (an asset/file id usable in edit_project), which the 'so edit_project can place it' clause only implies.

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 projectId are documented, but url is bare. The description compensates by defining what a valid url is (a stock-media or music search result link). It does not address the 2000-character limit or whether signed/redirect URLs are acceptable.

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 and resource: 'Copy an image, video clip or audio file from a link ... into a project's storage.' It also states downstream purpose ('so edit_project can place it'), which distinguishes it from read_project, list_projects and the search_* siblings by naming the exact sibling it feeds.

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 a clear when ('links such as a search_stock_media or search_music result') and an explicit when-not ('Links from elsewhere on the web are refused'), so the agent knows which URL sources are admissible. It does not compare against any alternative way to get content into a project, but no such alternative is evident from the sibling list.

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