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

No annotations are supplied, so the description must carry the full behavioural burden. It discloses one useful trait — a signed-wallet trial gate implying payment/authentication — but says nothing about whether the operation is pure/read-only, which algorithm is the default, or what happens with unsupported algorithms.

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 statement is front-loaded in a single compact sentence with no filler. The appended trial/emoji line is marketing rather than specification, but it is short enough to be tolerable.

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 two-parameter utility with no output schema and zero schema descriptions, the definition omits everything an agent needs beyond the tool's name: default algorithm, accepted value set, required inputs, and return shape. It is under-specified relative to what the absent structured data would otherwise cover.

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 both parameters (`algo`, `text`) are undocumented in structured fields. The description partially rescues `algo` by naming example values, but `text` is never mentioned, nor is whether `algo` has a default or is required (required count is 0 for both).

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?

It gives a concrete verb and resource ('Compute hash digests') and names concrete algorithms (SHA256, MD5), so the core operation is unambiguous. However, it never distinguishes itself from nearby siblings like `x402-fnv-hash` or `x402-hash-generator`, which an agent would have to compare on schema alone.

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 guidance on when to choose this over alternative hashing tools, nor any stated prerequisites. The only usage-adjacent information is the free-trial note, which is about billing, not about selection between tools.

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