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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint=false and destructiveHint=false, so the safety profile is carried by structured data. The description adds one genuinely useful behavioral fact beyond that: access is limited to notes owned by the linked account. It says nothing about what happens on a missing/unauthorized note (error vs empty).

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 short sentences, the core action first and the access constraint second. No filler and nothing that could be trimmed without losing information.

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 single-parameter read tool whose annotations cover safety and idempotency, the description plus schema is nearly sufficient. The remaining gap is the undocumented note_id format and the unspecified failure behavior for unowned or nonexistent notes.

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?

There is a single required note_id parameter with 0% schema description coverage, so the schema contributes nothing about its format. The description only indirectly ties it to "a note selected by the user"; it never states the ID format or where the agent obtains it. Partial compensation for the coverage gap, not full.

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?

"Reads the full content of a note" gives a specific verb and resource, and "selected by the user" conveys the retrieval model. It does not distinguish itself from siblings like get_note or search_notes, so an agent cannot tell from the description alone which read tool to pick.

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 phrase "note selected by the user" implies a UI-selection context and the ownership sentence states a prerequisite, which is useful. However there is no explicit when-to-use guidance versus get_note or search_notes, and no statement of what to do when the user has not selected a note.

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