ZIP create / extract / list

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

With annotations only flagging readOnly=false, openWorld=false, idempotent=false, the description supplies the meaningful behavior: symlinks skipped, folder names preserved as top-level folder, zip-slip refusals for '..'/absolute paths/drive letters, existing files kept unless overwrite=true, and no support for encrypted ZIPs. It also states hard limits (500 MB, 10000 entries) that the annotations cannot express.

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?

Front-loaded with the action taxonomy, then limits, then unsupported cases – a sensible order with no filler sentences. Density is high because of parenthetical clauses, but every clause (symlink skipping, zip-slip refusal, default caps) conveys non-obvious behavior.

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 an 8-parameter, multi-mode tool with no output schema, the description still covers each mode's inputs, default destinations, safety behavior, hard caps and an unsupported case. The 'list' mode's return shape ('entry names with sizes') is described, so nothing essential an agent needs before calling is 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 coverage is 88%, so the baseline is 3; the description earns above that by adding meaning the schema does not, notably that create paths are local paths whose folders keep their own name, that multi-part sizes are capped by maxTotalMB/maxFiles, and that extract's output defaults to the server output folder. It does not restate the level or overwrite semantics beyond what the schema already documents.

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?

Opens with a specific verb+resource ('Work with ZIP archives locally') and then enumerates the three actions with concrete effects (zip, unpack, entry names with sizes). No sibling tool in the list touches archives, and the action breakdown makes the scope unmistakable.

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?

Each action carries an in-line statement of what it does and its constraints, which implicitly routes the agent between create/extract/list ('list: entry names with sizes, no extraction'). It does not name exclusions or prerequisites (e.g. when a caller should prefer a non-local upload path, or required filesystem access), so it falls short of explicitly stating when-not to use it.

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