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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds genuinely new behavioral context the annotations do not: that the call is metered/paid via x402 when payments are enabled, with a pointer to quantum_pricing for current terms. It stops short of stating caching behavior or whether results are versioned/time-stamped, which would have made it a 5.

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?

One front-loaded sentence delivering the resource, the concrete standards covered, the algorithm list, and the source-link promise, plus a short payment clause. The standard identifiers are dense but each earns its place by telling the agent exactly what regulatory content comes back. No filler or restated title.

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?

An output schema exists, so return structure need not be explained, and read-only annotations cover the safety side. For a zero-parameter reference tool, the remaining agent needs are what content is included and how billing works, both of which are addressed. Minor gap: no indication of how current the timeline data is or whether it is cached.

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 takes zero parameters, so the schema baseline is 4 and there is no parameter meaning left to explain. The description correctly spends no words on inputs and instead characterizes the payload content, which is the useful information for a no-arg tool.

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 precisely what the tool returns: the U.S. federal post-quantum timeline with named sources (EO 14409, OMB M-26-15, NIST IR 8547 draft, NSA CNSA 2.0), the approved replacement algorithms, and links to sources. That is a specific verb+resource pair that clearly differs from siblings such as pqc_scan_code or pqc_crypto_inventory, which act on artifacts rather than serving reference material. It does not explicitly say which sibling to use instead, which keeps it out of the 5 tier.

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?

Usage is implied by the content: this is a static reference lookup, so an agent should call it when it needs deadline dates or approved algorithms rather than scanning. There is no explicit when-to-use or when-not-to-use guidance, and no routing statement contrasting it with pqc_readiness_package or pqc_crypto_inventory. The only explicit conditional is payment-related ('Paid per call via x402 when payments are on'), not usage-related.

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