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

Despite annotations already covering read-only/idempotent/non-destructive, the description adds rich behavior: it does not open the link, does not record a view, does not spend the recipient's unlock attempts, has its own separate rate limit of 20 checks per link per 5 minutes, and flags result text as untrusted author-written content. This is substantial context beyond the safety hints.

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-loads the core purpose and then explains return fields, which is appropriate given there is no output schema. It is dense and long with several chained clauses, but nearly every sentence carries distinct information and nothing is obviously redundant.

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 compensates by explaining each returned field (passwordEnabled, matches, linkStatus, opensLink) and the archived-document behavior. Combined with permissions, rate limits, and side-effect disclosure, an agent has everything needed to call and interpret this tool correctly.

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 docId, linkId, and password are already documented in the schema. The description explains return-value semantics but adds no parameter-level detail (formats, constraints, edge cases for the inputs) beyond what the schema provides, so the baseline 3 applies.

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+resource: 'Test whether a password opens a share link,' with the valuable qualifier 'without revealing what the real one is.' An agent can immediately tell this apart from unlock-attempt or password-setting tools, and the description explicitly notes it is separate from the recipient's unlock limit.

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 concrete usage context ('after setting it or before passing it on') and states the permission requirement (owner or admin of the key's own workspace). It stops short of naming a specific alternative tool or an explicit when-not-to-use condition, so it is clear context without full routing guidance.

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