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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior. The description adds genuinely new behavioral context beyond them: the ownership scoping constraint and the redaction guarantee that the existing passcode and hash are never returned, which an agent could not infer from the annotations.

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?

Two tight sentences with no filler. The positive statement of what is returned is front-loaded, followed immediately by the negative guarantee, which is exactly the right ordering for a read tool.

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 carries the burden of describing returns, and it does name the returned fields (capture fields, expiry, hasPasscode) plus what is withheld. It stops short of describing field types or the empty/absent case, but it is complete enough to invoke 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 0%, so the schema does not explain the single 'id' parameter. The description does not describe it either, but the parameter is a self-evidently named UUID identifier, so the gap is minor rather than severe. It neither compensates for nor worsens the coverage gap.

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 (read) and resource (saved reader settings for a document) and enumerates the returned fields (capture fields, expiry, hasPasscode). It is clearly distinguishable from update_document_reader_settings and get_document, though it never names those siblings 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?

'for an owned document' implies a precondition (ownership scope) that helps the agent decide applicability. However, there is no explicit when-to-use versus update_document_reader_settings or get_document, and no stated exclusions, so usage is only implied.

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