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

Annotations (readOnlyHint=false, destructiveHint=false) are consistent with a non-destructive but state-changing operation. The description adds genuinely useful context beyond them: the link is public, anyone with it can view, and access ends on unshare or expiry — key facts for judging exposure risk.

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 operation and reads as a compact Args/Returns block with no filler sentences. The leading 'Free.' is slightly awkward as an opener but still conveys pricing information an agent may care about.

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 one-parameter tool with no output schema, the description covers the operation, its public/expiring semantics, and the returned fields (ok, slug, share_url, kind) inline. Nothing material is left for the agent to guess before invoking it.

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?

The single parameter is fully documented in the schema (100% coverage), so the baseline is 3. The description's 'library_id: from library_list' essentially repeats the schema's 'The generationId from library_list', though it does mildly reinforce the provenance chain from the list tool.

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?

Names a specific verb and resource ('Make a public share link for one WEB Library item') plus scope qualifiers (WEB items only, one item per call). It hints at the inverse operation ('until you unshare it'), which helps separate it from library_unshare, though it never names that sibling explicitly.

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?

Implied usage is recoverable: use this when you want public, link-only viewing rather than a private fetch, and 'Free' signals no cost barrier. There is no explicit when-to-use/when-not statement and no named alternative such as library_unshare, so the agent must infer the routing.

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