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

Annotations already declare readOnlyHint=false, idempotentHint=true, destructiveHint=false, so mutation semantics are partly covered; the description adds real value with the 10 MB per-call cap and the instruction to call again for larger sets, plus the warning that upload alone does not place anything. It is silent on overwrite/collision behavior for an existing file name, which is the one behavioral gap.

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 compact sentences, front-loaded with the core action and the 'without placing them' distinction before the follow-up workflow. The embedded JSON snippet is dense but functional; a semicolon-chained middle clause takes slightly more parsing than necessary.

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 nested-object upload with no output schema, the description covers purpose, the follow-up step, and the payload-size constraint. It omits the return value (media identifiers) and duplicate-name handling, which are the remaining things an agent would want before calling.

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%, so the baseline is 3; the description earns extra by clarifying that the deck's library is 'a folder of photos they gave you' and that the file name supplied in the map is the name later referenced by edit_slides ('<name it answers>'). It adds no format detail beyond what the schema's files description already lists.

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: adds the user's own pictures and videos into a deck's media library, explicitly 'without placing them.' That clause alone separates it from edit_slides, which places media on a slide, so an agent can pick 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 routing: 'get lists the library' and 'then place one with edit_slides' with an example op payload. It stops short of an explicit negative case (e.g., don't call this to put an image on a specific slide) or a note on when to use rename/move for library files, but the intended workflow is unambiguous.

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