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

No annotations are supplied, so the description carries the full burden. It usefully discloses that the operation is local CPU work and instant, but says nothing about what is returned (boolean plus algorithm label?), what happens when digest lengths differ, or how ambiguity between algorithms of equal length is handled.

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?

Two short sentences with the core operation front-loaded and the secondary capability immediately after. No filler or restated title.

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 and no annotations, the description should clarify the return shape and the single-argument mode; it does neither. It is adequate for a trivial pure function but leaves the agent guessing about results when 'b' 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 coverage is 100% for the two parameters, so the baseline is 3. The description adds the concept that digest length drives algorithm detection, but it never explains why only 'a' is required while 'b' is optional, which is the single most behaviorally relevant parameter fact.

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 states a specific verb and resource (compare two hashes) plus a second distinct capability (identify the algorithm from digest length). That is enough to separate it from the generation siblings like hash and hash_text, though it never names those siblings explicitly.

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?

There is no when-to-use or when-not-to-use guidance and no alternative named. An agent must infer from 'compare two hashes' whether this is the right tool versus text_diff, compare, or hash; the only hint is the 'pure CPU, instant' performance note.

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