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

Annotations already declare readOnlyHint, idempotentHint, and openWorldHint=false, so the safety profile is covered. The description adds useful context by noting the inclusion of a data date and a weekly-change summary, but it does not disclose further behavioral traits like response format, caching, or update frequency.

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 front-loaded with the core purpose and uses a single, dense sentence to enumerate the readings. While the nested parentheticals make it slightly heavy to parse, every clause adds substantive detail about the returned content without repetition.

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 no output schema and no parameters, the description carries the burden of explaining what is returned. It names the four main reading categories and the weekly-change summary, which is sufficient for an agent to understand the tool's output surface, though it does not detail exact fields or formatting.

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 tool has zero parameters, and the schema is empty by definition. Per the established baseline, a parameterless tool receives a 4 because there are no parameter semantics for the description to clarify.

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 clearly states it returns today's Isoba readings with a data date, and enumerates the specific components (Dollar System Index, Crisis meter, market-top risk, recession risk, weekly changes). It distinguishes itself from siblings implicitly through 'today's' and 'this week,' but does not explicitly contrast with get_monthly_history or get_track_record.

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?

There is no explicit guidance on when to use this tool versus alternatives. The description only lists what the readings contain; it does not say to use it for current snapshots rather than historical tools, nor does it mention any prerequisites or exclusions.

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