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

Annotations declare write/idempotent/non-destructive, and the description adds substantial behavior beyond them: the owner cannot be changed, going restricted resets allowCopies to allowed, added people are emailed unless notify is false, and the current sharing is returned. These are exactly the side effects an agent needs before invoking a mutation.

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?

One front-loaded sentence plus a return statement and endpoint, with no filler. It is dense with parentheticals, which slightly taxes readability, but every clause carries operational meaning.

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 6-parameter mutation tool with no output schema, the description covers what changes, the constraints on each field, the default notification behavior, and what is returned. Nothing an agent needs before calling it 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 100%, so the baseline is 3; the description goes further by stating cross-parameter constraints the schema lacks: allowCopies applies only to public links and resets when restricted, viewLevel 'chat' requires a paid plan, and the owner entry is immutable. Only the notebook id parameter is left to the schema.

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 and resource ('Share a notebook or change its sharing') and then enumerates every mutation surface: people roles, link access, allowCopies, viewLevel. An agent can immediately distinguish this from the read-only sibling notebook_get_sharing.

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?

The context of use is clear: it both creates sharing and changes it, and it returns the resulting state. It does not explicitly name an alternative (e.g., notebook_get_sharing for reading without mutation) or state when not to use it, so it stops short of full routing guidance.

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