b2_create_key

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

The description adds meaningful behavioral context beyond the annotations: it explains how the secret is handled in file sink mode versus inline mode, and what the MCP response contains in each case. This is valuable because the tool is destructive and non-idempotent, and the secret-handling behavior is not obvious from annotations alone.

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 compact and front-loaded with the core purpose. Each sentence adds value, particularly the mode-specific secret-handling details, though terms like 'file sink mode' and 'inline mode' are introduced without explanation.

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 no output schema, the description does a decent job explaining response contents, but it leaves ambiguity about how an agent determines which mode (file sink vs inline) is active. Required parameters like confirm and idempotencyKey are covered by the schema, so the main gap is the mode-selection 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 description coverage is 100%, so the schema already documents all eight parameters. The tool description itself does not add parameter-level detail, matching the baseline score for a fully documented 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?

The description states a specific verb and resource: 'Create a B2 application key.' This clearly distinguishes it from sibling tools like b2_delete_key and b2_list_keys, though it does not explicitly contrast against them in text.

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 intended use is implied by the tool name and first sentence: use when you need to create a B2 application key. However, there is no explicit guidance about when to prefer this over related key-management tools or any exclusions.

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