md5sum

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

Declares 'Read-only, no side effects' which aligns with readOnlyHint=true. Also adds return format 'JSON with per-file hash values and byte counts' beyond annotations.

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 sentences, each serving a distinct purpose: what it does, behavior, and usage guidance. No wasted words.

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?

Given single parameter, clear annotations, and description covering purpose, behavior, alternatives, and return format, the tool is fully understandable without extra context.

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 covers all parameters (100% coverage) with clear description of 'paths' array accepting files or '-'. Description adds no new parameter info beyond restating input sources.

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 'Compute MD5 hash digests of files or stdin' – clear verb+resource+input sources. Distinguishes from sibling sha256sum by specifying non-cryptographic use.

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?

Explicitly says 'Use for fast non-cryptographic integrity checks... Not for security... use sha256sum or b2sum for security.' Provides alternatives and when-not-to-use.

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