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

Adds substantial value beyond annotations: the practical-collision warning and legacy-only suitability, determinism, no network/no stored state, and concrete limits (1 s per call, 1 MB result). One flaw: it says 'JSON input up to 64 KB' while the schema allows maxLength 1048576 (1 MB), an internal inconsistency that could mislead on payload sizing.

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 each clause earns its place, but the entire description is duplicated in Spanish and English, roughly doubling length with zero added information for a reader of either 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?

With annotations covering read-only/idempotent/no-network safety, 100% schema description coverage, and an output schema present so return format need not be explained, nothing an agent needs in order to call this correctly is missing.

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 enums are documented with defaults, so the schema carries parameter meaning fully. The description says nothing about input_encoding/output_encoding beyond the implied 'text or bytes', so per the baseline rule a 3 is correct.

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?

States a specific verb and resource ('Computes the SHA-1 digest (160-bit)') and pins the digest size, so it is unambiguous against the many sibling hash-* tools. It also names the sibling it is not (hash-sha256) in the same breath.

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?

Gives explicit when ('compare content or match a published checksum', legacy interop like git object IDs) and explicit not-for ('not for signatures', use hash-sha256 for SHA-256). The alternative is named by tool id, leaving nothing to infer.

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