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

Annotations already cover the safety profile (readOnly, non-destructive, closed-world), and the description adds value beyond them: determinism guarantees per algorithm, the exact return shape (hex digest + algorithm + byte count), and a clear cost model including that failed calls are not charged. What it omits is what happens on unsupported input or how large inputs are 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?

Three tight sentences, front-loaded with purpose, then implementation detail, then return/cost semantics. No filler, and each clause carries distinct 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?

Return values and cost are fully covered, so no output schema is needed. The unresolved gap is input: an empty object schema plus a description that never says what content is hashed or how the algorithm is selected leaves an agent unable to construct a correct call from the definition alone.

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?

With zero parameters, the baseline is 4; however, the description advertises three selectable algorithms (sha256, xxhash64, murmur3) that have no corresponding schema field, leaving the agent unsure how an algorithm is chosen. That ambiguity lowers it below baseline rather than raising it.

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?

'Content-addressable hashing for caching and dedup' names a specific operation and its purpose, which cleanly separates it from siblings like chunk, dedupe, and diff. It does not explicitly contrast with a sibling, but the resource and verb are unambiguous.

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 phrase 'for caching and dedup' implies the contexts where this tool applies, but there is no explicit when-to-use versus when-to-use-an-alternative guidance, nor any statement of prerequisites or exclusions relative to the 12 sibling tools.

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