generate_mnemonic

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

Annotations already mark the tool as read-only and non-destructive. The description adds meaningful behavioral context beyond annotations: it works offline, requires a specific environment variable, returns the phrase into the conversation/transcript, and carries security caveats. This is helpful transparency, though not exhaustive about internal generation behavior.

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 purpose, then concise caveats and parameter documentation. Every sentence adds value, with no filler or redundant restatement of the tool name.

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 one optional parameter and an output schema present, the description covers prerequisites, security behavior, and valid arguments. Nothing critical is missing for an agent to understand how to call the tool correctly.

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 provides no description for word_count (0% coverage), so the description fully compensates by enumerating valid values (12, 15, 18, 21, 24) and stating the default. This is essential for correct invocation and goes far beyond the bare schema.

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 ('Generate') and a specific resource ('BIP-39 seed phrase'), making the tool's purpose immediately clear. It also distinguishes itself from the sibling validate_mnemonic by focusing on creation rather than validation.

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?

Provides clear context: use when a new mnemonic is needed, it works offline, and MCP_BITCOIN_ALLOW_MNEMONIC=true is required. It does not explicitly name alternatives like validate_mnemonic for when-not-to-use this tool, but the warning about not using the result for real funds adds an important usage boundary.

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