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

Annotations already establish read-only, idempotent, and non-destructive behavior. The description adds the cost of $0.001 USDC and the Base/Solana payment context, which are not captured by the annotations. Payment mechanics are not fully explained, but for a pure hash function this extra disclosure is valuable.

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 description is short and front-loads the pricing, but it is a telegraphic fragment rather than a sentence, making 'Paid $0.001 USDC on Base or Solana SHA-256 digest' awkward to parse. There are no wasted words, but the structure hurts clarity.

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 simple single-parameter tool with annotations, the description covers input type, boundedness, cost, and network context. It does not specify the return encoding (e.g., hex) and has no output schema, though 'SHA-256 digest' partly implies the output.

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 schema only provides a string maxLength with no parameter description, so the description's 'bounded UTF-8 text' adds meaning to the single input parameter. It is still implicit rather than explicit about the parameter named 'input' being the text to hash.

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 the exact operation: produce a SHA-256 digest from UTF-8 text. It is distinguishable from sibling tools like sha512, keccak256, and hmac_sha256 because it explicitly names SHA-256, though it lacks an explicit verb phrase.

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 algorithm name and the phrase 'digest of bounded UTF-8 text,' so an agent can infer when to call this tool. However, there is no explicit guidance about when not to use it or how it compares with related hash tools.

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