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

Even though annotations already mark this as destructive, the description adds crucial specifics: existing paths are overwritten, limits of 900 files per call and 10,000 per drop, and the drop retains its expiry and password protection. This is exactly the kind of behavioral context that goes beyond the annotations.

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?

One dense, well-structured sentence that front-loads the purpose and then packs in the most important constraints. Every clause adds value, with no filler or repetition of schema details.

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 annotations, a rich input schema, and an output schema present, the description provides all critical operational context: authentication, subscription requirement, file count limits, overwrite behavior, and preservation of expiry/password. Nothing essential is missing for an agent to call this tool correctly.

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 schema already documents both parameters. The description adds meaningful parameter-level constraints: up to 900 files per call and 10,000 per drop total, plus overwrite semantics for existing paths. This goes beyond the baseline schema documentation.

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?

The description states a specific verb and resource ('Add files to a drop') and clarifies ownership and authentication. It does not explicitly distinguish itself from sibling tools like deploy_files, but the title's 'append to an existing drop' plus the description's focus on adding to an owned drop make the purpose clear.

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 description gives clear context: the drop must be owned by the authenticated account, and an sp_ API key with an active subscription is required. It does not explicitly name alternatives or exclusions, but the ownership and authentication context is strong enough to guide appropriate use.

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