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

No annotations, so the description carries the full burden, and it does: discloses the cost model (free via x402), the exact return payload (changed_count, next_cursor, as_of, no rows), and the recommended polling cadence. This is materially more than the schema provides and directly shapes how the agent should behave.

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-loaded with 'Free' and the core purpose, and each sentence carries weight (return shape, polling strategy). The trailing bracketed HTTP/pricing/docs metadata is useful but slightly less essential, keeping it just under full marks.

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?

For a single-parameter, no-output-schema tool, the description is complete: it explains the response fields the missing output schema would otherwise cover and clarifies the free-vs-paid workflow. An agent has everything needed 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 description coverage is 100%, so the 'since' cursor is already fully documented in the schema ('Opaque cursor from a previous next_cursor; omit once to bootstrap'). The description only restates 'since your cursor', adding no syntax or edge-case detail beyond the schema; baseline 3 applies.

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+resource with scope: a count of econ observations printed or revised since a cursor. It explicitly distinguishes itself from its closest sibling (econ_dashboard_delta) by noting it returns 'changed_count, next_cursor, and as_of only — no rows', so an agent can route between the free probe and the paid delta without opening either schema.

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?

Gives an explicit when-to-use and when-not: poll hourly for $0 and only call the paid delta when changed_count > 0. The alternative (delta) is named and the gating condition is spelled out, leaving nothing to inference.

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