Encrypt text (AES-256-GCM)

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

Goes well beyond annotations with KDF details (PBKDF2-SHA256, 600k rounds, random salt/IV), the 'S3E1…' output format, and the non-determinism note ('Each run gives a different output') which aligns with idempotentHint=false. The only tension is that readOnlyHint=true while the optional output param can write a file — disclosed but arguably inconsistent with the annotation.

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?

Front-loaded with the core verb and algorithm, and every clause adds real information (rounds, IV, format, interop). The website URL is repeated twice, a minor redundancy that keeps it from a 5.

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?

Covers algorithm, key derivation, output format, non-determinism, and how to reverse the operation. With no output schema, the description fully specifies the returned 'S3E1.…' line, so an agent has everything needed.

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 each of the 5 params is already documented, and the description adds no syntax or format guidance beyond implying defaults. Baseline 3 is appropriate when the schema carries the parameter burden.

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+resource (encrypt a message with a password) and pins down the exact scheme (AES-256-GCM). It clearly distinguishes itself from the file sibling crypto_file_encrypt and names its inverse crypto_text_decrypt, so an agent can route without opening the schema.

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 names the counterpart tool crypto_text_decrypt and the website as the decryption path, and explains the interoperability constraint. It doesn't spell out when to prefer it over crypto_file_encrypt (file vs. inline text), but the intent is clear from the resource.

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