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

Goes beyond the annotations (readOnly, idempotent, non-destructive, closed-world) by adding that there is no network access, no stored state, deterministic output, and concrete limits (64 KB input, 1 s per call, 1 MB result). Minor friction: the stated 64 KB input cap does not line up with the schema's 1 MB maxLength on `data`, leaving the real input bound slightly ambiguous.

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 content is front-loaded and well structured (When / Not for / Side effects / Deterministic / Limits), but the entire description is duplicated verbatim in Spanish and English, roughly doubling the token cost for any agent that only needs one language.

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?

An output schema exists, so return values need not be explained, and the description covers safety, determinism and limits. What is missing is small but real: nothing says how `input_encoding` interacts with the size limit or what the output field looks like for a large result.

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% and both parameters, including the utf8/hex/base64 enum and its default, are documented in the schema, so the baseline of 3 applies. The description adds nothing about `input_encoding` or how the declared size limits relate to the `data` field, so it does not earn more than 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?

Names a specific verb and algorithm ("Computes the CRC-32 (IEEE 802.3, as in zip/gzip/PNG)") and qualifies it as a non-cryptographic checksum, which lets an agent separate it from the hash-* family. It explicitly disowns hash-sha256, but does not distinguish itself from the nearest siblings (checksum-crc32c, checksum-adler32, checksum-fnv1a32), so an agent choosing within the checksum family still has to infer.

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?

Provides an explicit "When" clause (fast non-cryptographic checksum for error detection, sharding, hash tables) and an explicit "Not for" clause naming hash-sha256. Use/avoid conditions and the alternative are both stated, leaving nothing to inference.

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