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

Annotations already declare readOnly=false, idempotent=false, destructive=false, openWorld=false, so the safety profile is covered. The description adds genuinely useful non-obvious context: the backend (Cloudflare Edge KV) and the x402 payment of $0.001 USDC, which signals an auth/cost step an agent must anticipate. However, it omits how the stored state is identified or retrieved, which matters for a non-idempotent write with no output schema.

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?

A single front-loaded sentence with no filler. The core action, backend, TTL configurability, and cost are all packed in without redundancy.

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 non-idempotent write tool with no output schema, the description leaves critical gaps: it never says whether a key/ID is returned, how the state is later read back, or how the x402 payment handshake works. Given no sibling offers retrieval, an agent cannot tell how this tool fits into a workflow.

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 both parameters, so the schema already documents 'data' and the TTL range (60-86400). The description's 'custom TTL' adds no detail beyond the schema, so the baseline of 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?

The description names a concrete verb and resource: 'Store temporary JSON state in Cloudflare Edge KV.' Combined with the TTL detail, an agent knows exactly what the tool does. Sibling differentiation is not explicitly stated, but no sibling (content_digest, dom_snapshot, extract_json, llm_router, quant_regime, refine_url, verify_links) overlaps with a KV store, so confusion risk is low.

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?

There is no explicit when-to-use guidance, no exclusions, and no alternative named. The word 'temporary' implies a short-lived use case, but nothing tells the agent when ephemeral KV is preferable to other persistence, nor how to choose a TTL value. This is implied usage at best.

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