Hash a string with crypt.hash (sha1/sha256/sha384/sha512/md5)

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

Annotations already declare readOnly/idempotent/non-destructive, yet the description adds genuinely new behavioral facts: it runs entirely in-game via the executor's crypt.hash, it is pcall-guarded, and on an executor lacking crypt.hash it returns { error } instead of throwing. Those failure semantics are not derivable from the annotations.

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 behavior and error semantics are front-loaded in the first two sentences. The trailing 'Phase/cost/idempotency/Safety/On failure' block is somewhat redundant with the annotations and footer-ish, but the overall structure remains scannable.

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?

With no output schema, the description steps in to define the return shape ({ hash, algorithm } or { error }) and the failure path, and it points to tool-schema for exact fields. An agent has everything needed to call it correctly.

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 100%, so the schema already documents data, algorithm (with enum + default), timeoutMs, and threadContext. The description restates the signature and adds only the note that the result is a hex digest string, which is marginal beyond the schema baseline.

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+resource ('Compute a cryptographic digest of a string') and enumerates the exact algorithm surface (sha1/sha256/sha384/sha512/md5) plus the default. This clearly separates it from adjacent siblings like crypt-encrypt, crypt-base64-encode, and generic execution tools.

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?

Gives useful context for invocation: phase=observe, cost=medium, requires active-client, and that the tool degrades gracefully rather than throwing. It does not explicitly contrast against alternatives such as run-luau or execute-lua-state, which is the only real gap.

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