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

With no annotations provided, the description carries the full burden and does so richly: pricing tiers (3 free/day, then 0.005 USDC via x402 on Base), the client-support requirement, TTL semantics, and the security caveat that hosted mode briefly sees plaintext over TLS while the local server is zero-knowledge. This is exactly the behavioral context an agent needs before calling.

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 core purpose is front-loaded and the sentences are dense with non-redundant information (pricing, security model, return values, sibling routing, server alternative). It is lengthy, but nearly every clause earns its place; minor trimming is possible in the security paragraph.

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?

No output schema exists, yet the description specifies the return shape ({ link, id, receiptToken, expiresAt }) and what to do with the returned id and receiptToken. Combined with the usage, pricing, and security notes, nothing essential for calling the tool correctly is missing.

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 is 100%, so the baseline is 3. The description adds meaning beyond the schema by tying ttl_seconds to pricing tiers ('first 3 per day are free (TTL up to 24h)') and by framing passphrase as a second factor shared through a different channel, which constrains how the agent should supply it.

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 and resource: 'Store a password, API key or sensitive note as a one-time link that self-destructs after a single read.' It distinguishes itself from siblings by naming ncrypted_status and ncrypted_burn as the follow-up tools for delivery checks and revocation.

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?

Explicitly covers when to use it (share one-time secrets with a person or agent), after-use guidance ('never echo the secret in chat'), and a named alternative for the zero-knowledge case (the local MCP server via npx). It also routes the agent to ncrypted_status/ncrypted_burn for post-creation actions.

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