zas_get_item

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

With no annotations, the description carries the full burden and does real work: it discloses that notes come back as text while files are written to disk, that it never overwrites an existing file, that the returned path can differ from dest, and that the default destination is a temp directory. It omits auth/permission needs, but the destructive-safety profile is well covered.

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?

The core action is front-loaded and the file-writing caveats follow logically. The closing sentence about the owner seeing every item this agent sends is tangential for a fetch tool and is the one sentence that does not clearly earn 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?

With no output schema, the description correctly explains the return value (the written path, which may differ from dest) and the note-vs-file duality. It is essentially complete for correct invocation, missing only edge behavior such as what happens when the id does not exist.

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 channel, id, and dest semantics. The description's added detail ('writes a new file under dest... never overwrites') is really return-value behavior rather than new parameter meaning, so the baseline 3 holds.

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 opens with a specific verb+resource: 'Fetch one item from a Zas channel.' The word 'one' implicitly contrasts with the sibling zas_list_items, so an agent can distinguish retrieval-by-id from enumeration 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?

Usage is implied rather than stated: the tool is clearly for pulling a single item given a channel and id. There is no explicit when-to-use/when-not guidance and no pointer to alternatives such as zas_list_items for discovering ids, so the agent must infer routing.

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