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

No annotations, so description carries full burden. It discloses determinism, no network, and pricing (x402 $0.003), which are useful behavioral traits. However, it omits critical details: encoding behavior, output format specifics, max input size (400k chars in schema), and error conditions.

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?

Extremely concise: one sentence covering hashing, algorithms, return format, determinism, network, and price. Front-loaded with core action and zero waste.

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 tool with no annotations, no output schema, and 0% schema description coverage, the description is insufficient. It omits encoding semantics, input size limits, and detailed parameter meanings, leaving the agent to guess about non-default encoding and large inputs.

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 0%, so description must compensate. It mentions 'algo' values (sha512, sha3_256, blake2b_256) but not the default 'sha256' explicitly (though implied by tool name and 'by default'). It does not explain 'text' beyond 'string', nor 'encoding' at all, leaving two parameters undocumented.

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?

Clear verb+resource: 'Hash a string' with specific algorithms named, and maps to the sha256 tool name. No sibling does hashing, so differentiation is implicit by name; the description could be slightly more explicit about being the only hash tool.

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?

Implies usage for hashing arbitrary strings, but doesn't state when to choose this tool over alternatives (none exist) or constraints like input size limits, which are in the schema. No exclusions or alternatives are given.

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