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

Goes well beyond the readOnly/idempotent annotations by disclosing the panel fallback for clients without panels, the full return shape, and the concurrency-control requirement to use expected_lock_version from the latest read before notes-update. This is behavior an agent cannot 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?

Purpose and trigger lead the description, followed by return shape, then fallback, then mutation caution. Dense but every sentence carries actionable information; only the trailing 'Optional: id (integer)' is redundant with the schema.

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 naming the returned fields and the degraded-mode response, and it covers the edit/optimistic-lock workflow. Nothing an agent needs to call it correctly 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?

Only one optional parameter with 100% schema coverage, and the schema already documents the omit-id picker behavior. The description restates the same semantics ('Without an id the panel opens on a note picker') without adding format or constraint detail beyond the schema, so the structured data is doing the work.

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 (open a note in the Hjarni note panel beside the conversation) and explains exactly how it differs from notes-get by enumerating the extra fields (space, can_edit, uri). An agent can distinguish it from notes-get, notes-panel and notes-list without opening any 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?

Gives explicit trigger conditions (user asks to open, show or work on a specific note) plus a prerequisite workflow (find the id with search first) and a follow-on constraint (pass expected_lock_version from your latest read before notes-update). Covers when to use it and what to do next.

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