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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered; the description adds genuinely new context: determinism and explicit operational limits (64 KB JSON input, 1 s per call, 1 MB result). The size limits are worth flagging because the schema's maxLength is 1048576 (~1 MB), which conflicts with the stated 64 KB input cap.

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?

Sentences are short, labeled (When / Not for / Side effects / Deterministic / Limits) and front-loaded, so an agent can scan for the routing decision quickly. The cost is a full Spanish/English duplication that roughly doubles length, though that appears to be a deliberate bilingual convention given the Spanish 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 a 100%-covered schema, full annotations and an output schema, the description carries only the burden of routing and constraints, and it does both. The only completeness gap is the input-limit figure disagreeing with the schema's maxLength, which could mislead an agent sizing its inputs.

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 baseline is 3. The description reinforces that input may be text or bytes and lists the digest algorithms, but it never explains the input_encoding parameter (utf8/hex/base64), which is the one parameter whose meaning is not self-evident from the name alone.

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 first sentence names a specific verb and resource — computing multiple digests (md5, sha1, sha256, sha512, etc.) of one input in a single call — and enumerates the algorithm set. This makes it immediately distinguishable from the single-algorithm siblings such as hash-md5 or hash-sha512.

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?

It gives an explicit 'When' (comparing content, matching a published checksum) and an explicit 'Not for' that routes to hash-sha256. The exclusion is only partial, since the sibling set contains hash-md5, hash-sha1, hash-sha512 and many others that are equally single-algorithm alternatives, but the usage context itself is clear and actionable.

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