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

Annotations already declare readOnly/idempotent/non-destructive, and the description adds meaningful context beyond them: the scope distinction between recent_notes (personal only) and recent_changes (across ALL spaces, newest edit first), the fixed count of 5, and the empty-state fallback to `me` for onboarding. No annotation contradiction.

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?

Front-loads the return composition, which is the most important information, and each sentence carries a distinct payload (contents, recommended usage, empty-state routing). It is slightly dense in the recent_notes/recent_changes parenthetical but nothing 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?

With no output schema, the description correctly takes on the burden of describing return values and their scoping; with zero parameters there is nothing else to document. The empty-account edge case is handled, so an agent has everything needed to call and interpret it.

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?

Zero parameters, so the baseline is 4. The trailing 'No parameters required.' merely restates the schema, which is already fully described at 100% coverage, so it adds no new meaning but is harmless and correct.

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 ('Get') and resource ('overview of the user's Hjarni account') and then enumerates exactly what is returned (counts of notes, containers, tags, inbox items; recent_notes; recent_changes). An agent can tell instantly that this is the account-summary tool and distinguish it from notes-list or search without opening sibling schemas.

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?

Explicitly tells the agent when to call it ('Use recent_changes to orient at the start of a conversation on what changed lately everywhere') and names the alternative for a specific condition ('if everything is empty... call `me` and follow onboarding.next_action'). This is exactly the when-to-use / alternative-routing guidance expected.

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