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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so safety is covered. The description contributes beyond that by disclosing ordering ('newest first') and the shape of the return ('returns each file's type'), which is genuinely useful for chaining to a post tool.

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 tight sentences, front-loaded with what is returned, then the trigger for calling it, then the chaining hint. No filler and no repetition of the title.

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 simple two-parameter read tool with no output schema, the description covers what is returned, the ordering, and when to invoke it – enough to call correctly. It stops short of explaining how the default 24-hour window or limit interact with pagination, a minor remaining gap.

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%, with both hours (window) and limit (count) documented inline, so the baseline is 3. The description adds no syntax or meaning beyond the schema for these parameters, which is acceptable given the schema carries them fully.

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 (list the URLs of recently uploaded files) and pins the source precisely as out-of-band uploads via an upload link or direct HTTP upload. That source scoping cleanly separates it from siblings like upload_file and search_my_images, so an agent can route to it without opening another 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 an explicit trigger: 'Call this after the user says they have finished uploading.' That is a clear when-to-use condition. It does not name an alternative or spell out a when-not case, which keeps it just 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.