sftp-upload-file

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

Annotations already mark destructiveHint=true, so the description need not repeat that. The description adds useful behavioral context beyond annotations: streaming behavior, the transferRoot configuration requirement, and refusal behavior when that setting is absent. This is solid added value.

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 sentences with no filler: purpose, constraint, and usage guidance are each front-loaded in their own sentence. Every clause earns its place.

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 moderate-complexity upload tool with full schema coverage and a destructiveHint annotation, the description covers purpose, constraints, failure refusal, and sibling routing. It does not describe return behavior, but no output schema exists and the schema covers parameters; the remaining gaps are minor.

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 the schema already documents all five parameters. The description reinforces that localPath must be within transferRoot, which the schema also says, but it does not add new parameter-level semantics. Baseline 3 is appropriate.

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 the specific operation ('Upload a local file to the remote host over SFTP') and adds a distinguishing trait: streaming without passing contents through model context. It explicitly contrasts with sftp-upload, making its purpose unmistakable among siblings.

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?

It gives clear when-to-use guidance ('binary or large files') and names the alternative for the other case ('use sftp-upload for short text you already have'). It also states a hard prerequisite: the local file must be inside transferRoot, otherwise the tool refuses.

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