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

Annotations cover the safety profile (readOnlyHint, destructiveHint=false, openWorldHint), and the description adds real value beyond that: the tiered auth behavior for non-USD currencies, the subscribe path, and the explicit caveat that the factor is a documented summary and does not replace underlying releases. It stops short of describing pagination or response shape, but the output schema covers returns.

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 purpose sentences followed by one access sentence; the primary action and scope are front-loaded and every sentence carries information an agent needs (the summary-vs-source caveat and the access rule). No filler.

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 an output schema present, return values need no explanation, and the description covers the one non-obvious operational fact (auth tiers). The only gap is that it does not hint at the set of valid factor slugs beyond the schema's single 'monetary_stance' example, which matters for the required 'factor' argument.

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?

Schema description coverage is 100% for all 8 parameters, so the schema already carries the semantics and baseline 3 applies. The description's mention of 'stored component scores and source references' loosely maps to include_components/include_sources but adds no syntax, defaults, or factor-slug guidance beyond the schema.

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 ('Return a precomputed macro factor for one currency') plus the optional enrichments it can carry (component scores, source references). It is distinguishable from sibling tasks like macro_briefing_task or indicator_query, though it never names an alternative to sharpen the boundary.

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 gives the access condition (USD free, all other currencies return subscription_required with a subscribe link), which is genuinely actionable context. However, it never says when to reach for this tool versus indicator_query, rate_differentials, or the macro_* task siblings, so usage is only implied.

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