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

No annotations are provided, so the description carries the burden; it does disclose the output shape ('hex digest'), which is the main behavioral trait beyond the schema. It does not say that the operation is pure/non-mutating, that results are deterministic, or that no external state is touched — reasonable inferences, but left unstated.

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?

A single front-loaded sentence listing the operation and output format with zero filler. Nothing could be removed without losing information.

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, non-mutating utility with no output schema, the description plus enum covers almost everything an agent needs. The one meaningful omission is the default algorithm, which the agent would have to read from the schema to know what happens when `algo` is omitted.

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 the description must compensate; it does partially by naming the four algorithms that map to the `algo` enum and by stating the input is a string. However, it never mentions the default (`sha256`), the `text` parameter name, or any format expectations for input, so coverage is only partial.

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 a specific operation and resource ('hex digest of a string') and enumerates the supported algorithms, which is enough for an agent to tell it apart from encoding (b64), casing (case), or ID generation (uuid) siblings. It stops short of explicitly contrasting with those siblings, so a 4 rather than a 5.

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 only implied: the description says what the tool computes but never states when to reach for it versus b64 or uuid, nor any constraint such as determinism or input encoding. For a trivially scoped utility the gap is small, but it is not explicit guidance.

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