zas_send_file

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

With no annotations, the description carries the full burden and does so: it discloses the async return shape (item id, or a job id when the upload exceeds a minute), a hard refusal condition for Directo channels, a capability boundary ('any file this process can read'), and an audit/visibility behavior ('owner sees every item ... with the >_ agent mark and this agent's name, on every device').

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?

Four compact sentences, each carrying distinct information (action, return shape, refusal/alternative, safety warning, visibility), with the core action front-loaded and no filler.

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?

There is no output schema and no annotations, so the description must cover both; it explains the return values (item id vs job id), the refusal path, and the safety/visibility implications. Nothing an agent needs to invoke this correctly appears to be missing.

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 baseline is 3; the description adds meaning beyond it by tying the `channel` parameter to the Directo-mode refusal and by characterizing `path` as limited to files 'this process can read'. It does not restate the `expires_in_days` clamping semantics, but the schema already covers that well.

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 with scope: 'Send a file from this machine into one of the owner's Zas channels.' It also explicitly differentiates from a sibling by noting that a channel in Directo mode refuses this tool and that zas_send_direct should be used there.

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 exclusion rule ('A channel in Directo mode refuses this tool: use zas_send_direct there') naming the alternative tool, plus a safety precondition ('confirm with the owner before sending secrets, keys or credentials'). Both when-not-to-use and the alternative are stated outright.

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