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

With no annotations, the description carries the transparency burden. It discloses determinism, locality, stable JSON output, and even the HTTP x402 price. It does not cover null-input behavior, encoding, or input size limits, but these are minor for a simple hash utility.

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 compact and front-loaded: algorithm set, input form, determinism, locality, JSON stability, and cost all appear in a single efficient sentence. There is no filler or repetition.

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 single-parameter, output-schema-backed tool, the description covers the algorithm, input format, behavioral guarantees, and cost. The only gaps are edge cases like null text or maximum input size, so it is nearly complete but not exhaustive.

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's only parameter, text, has no description, so the description must compensate. It does so by connecting the parameter to the query syntax '(?text=)' and stating that any text is accepted. It does not explain the null default, but the intended usage remains clear.

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 ('SHA-256 and SHA-512 digests') and its input ('any text'), making the tool's function immediately clear. The algorithm set helps distinguish it from many siblings, though it does not explicitly differentiate from api_hash_multi.

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?

The description gives clear context: use this when you need SHA-256 or SHA-512 digests of arbitrary text, supplied via the ?text= parameter. It provides no when-not-to-use guidance or alternative routing, but the common usage case is explicit.

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