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

Annotations already cover safety (readOnly, idempotent, non-destructive, openWorld), so the bar is lower. The description adds genuinely new behavioral context beyond them: this call does not return content directly but returns x402 payment requirements and a URL, which materially changes how an agent must handle the result. It stops short of explaining the payment flow or retry semantics.

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 short sentences, zero filler, with the paid nature and the return contract front-loaded. Every clause earns its place.

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 no output schema and 0% parameter description coverage, the description carries most of the burden. It discloses the key surprise (payment requirements instead of content) but omits the payment/retry mechanics and any detail on the 'to' parameter, leaving an agent under-informed about the actual call flow.

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 0%, so the description must compensate. It conveys that from/to form a date range, but adds no format, boundary, or open-endedness detail (e.g., whether 'to' is optional and defaults to now). The schema's regex does document the date format, so the gap is partially covered elsewhere.

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?

Names a specific resource ('archived briefs') and scope ('for a date range'), and states that it is a paid endpoint returning x402 payment requirements plus a URL. This distinguishes it reasonably from get_latest_brief and get_sample_brief, though it never names those siblings explicitly.

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 word 'archived' implies use for historical rather than current briefs, and 'Paid endpoint' signals a cost consideration, but there is no explicit when-to-use/when-not guidance or named alternative (e.g., get_latest_brief for the current brief). Usage is left to inference.

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