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

Annotations already declare read-only and idempotent hints. The description adds useful context: MD5 is excluded because it is broken and unavailable in Web Crypto, and LLMs cannot compute hashes reliably, making tool use necessary. This goes beyond the annotations without contradicting them.

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 description is three sentences: it states the action, lists use cases, and explains the MD5 exclusion and LLM limitation. Every sentence adds value, and the key action is front-loaded.

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 an output schema present and annotations providing safety profile, the description covers purpose, use cases, limitations, and parameter behavior. There are no significant gaps for this simple hashing tool.

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?

The input schema already covers both parameters with descriptions and an enum (100% coverage). The description reiterates the algorithm list but adds no new parameter-level detail, so it meets the baseline for high schema coverage.

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 description clearly states it computes a cryptographic hash of text using SHA algorithms and returns a hex digest. It is specific about the resource and action, but does not explicitly differentiate from the sibling hmac tool, so it falls short of a 5.

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 description gives explicit use cases ('checksums, cache keys, or verifying content') and states that MD5 is intentionally not offered. It does not mention alternatives like hmac or explicitly say when not to use this tool, so it is good but not fully explicit.

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