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

Beyond the annotations (readOnlyHint=false, destructiveHint=true), the description discloses the two-phase proposal/confirm protocol, the action_id and plan_token returned, the confirmation_required status, and the ownership boundary. That is exactly the kind of behavioral context an agent needs before invoking a mutating tool.

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?

Purpose is front-loaded, the ownership constraint follows, and the confirmation flow is signposted with a 'CONFIRMATION:' label. The final sentence is somewhat run-on with the status/action_id/plan_token detail, but no sentence is wasted.

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 with no schema descriptions and no output schema, the description covers every parameter, the access scope, and even the shape of the confirmation response. An agent has everything needed to call it correctly and handle the result.

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?

With 0% schema description coverage, the description compensates well: it identifies all six parameters including the required reading_id (via 'by id'), and states the accepted status values and 1-5 rating range. The enum and range restate schema constraints rather than adding new meaning, and the id's integer|string form is not clarified, keeping it below a 5.

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?

The description names a specific verb and resource ('Move one of the caller's reading items along by id') and enumerates the mutable fields (status/rating/title/url/notes), which cleanly separates it from add_reading and delete_reading without needing the schema.

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?

It clearly scopes use to the caller's own existing item and explicitly routes the completion step to confirm_action, specifying the status='confirmation_required' handoff. It stops short of naming add_reading/delete_reading as the alternatives for creation or removal, so exclusions rely on inference.

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