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

The readOnlyHint annotation already establishes non-destructive behavior, lowering the burden. The description adds useful context: all monetary values are in major units, and it explains why SQL composition is inadequate for the alert/headline logic. It does not disclose potential limitations like latency or pagination, but for a 0-parameter briefing tool, this is sufficient. No contradiction with 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?

The description is a single dense paragraph but front-loads the purpose and lists components clearly. It is not overly verbose and every clause adds value (content, units, usage guidance). It loses one point only because a bulleted or more segmented structure might improve scannability, but the prose is efficient.

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?

Given the tool has no output schema, the description fully specifies the return components: net-worth change, budget alerts (with utilization threshold), transaction/transfer/asset activity, and a prioritized headline. It also states the unit of monetary values and provides usage context. An agent can invoke and interpret the result correctly without further detail.

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?

The input schema is empty (0 parameters), so the baseline is 4. The description correctly avoids inventing parameters and instead clarifies the return payload, which is the meaningful semantic content an agent needs. No additional parameter explanation is necessary.

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 states a specific verb ('Get') and resource ('yesterday's morning briefing') and enumerates the exact contents (net-worth change, budget alerts, activity, headline). It also explicitly contrasts with run_read_query, distinguishing itself from the most likely sibling and preempting confusion. This is unambiguous and differentiated.

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 explicitly instructs to use this tool for 'what happened yesterday' / daily-digest style questions and tells the agent to use it 'instead of composing it from run_read_query', with a reason (alert thresholds and headline priority are not simple SQL). This is a clear when-to-use directive that also names the alternative, leaving no ambiguity about selection.

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