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

The description adds meaningful behavioral context beyond the annotations: it reveals the resumable-cursor polling pattern, the bounded nature relative to streaming, and the exact authentication failure behavior (subscription_required with a subscribe link). There is no contradiction with the annotations, which already indicate a read-only, open-world, non-destructive operation.

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 three tight sentences with no filler. The core action is front-loaded, followed by the critical polling pattern, and then the access requirement. Every sentence contributes essential information.

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 that there is a rich output schema and 100% parameter schema coverage, the description covers the remaining needed context: the tool's purpose, the cursor-based continuation pattern, its bounded behavior versus streaming, and the auth/subscription outcome. Nothing essential is missing for an agent to invoke it correctly.

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 coverage for parameters is 100%, so the baseline is 3. The description adds value beyond the schema by explaining the intended cursor workflow: 'use the returned next_cursor as since on a later call.' This gives practical meaning to the since parameter, though the other parameters are not discussed in the description.

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 opens with a specific verb and resource: 'Poll recently ingested macro announcement changes with a resumable cursor.' It clearly identifies what the tool does and explicitly distinguishes it from an unbounded streaming alternative by calling it the 'bounded MCP-safe companion to the release-event stream.' This is more than enough to differentiate it from sibling tools like latest_announcements or release_calendar.

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?

The description gives explicit usage guidance: use the returned next_cursor as the since parameter on a later call rather than holding an unbounded streaming invocation open. It also provides access guidance by stating that an FXMacroData API key is required and that anonymous calls return subscription_required with a subscribe link. This clearly tells the agent when and how to use the tool.

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