✓ SAFE: Open an existing database file. Sets as current context. Returns database info. Errors if file does not exist — use create_database to make a new one.

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

Discloses that it sets the current context, returns database info, and errors if file not found. With no annotations, this provides sufficient behavioral context for a simple tool.

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?

Single sentence, front-loaded with 'SAFE', no wasted words. Every part adds value.

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?

Provides key information: action, error case, result type. With one parameter and no output schema, the description is mostly complete, though could mention that it sets context for subsequent operations.

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?

Only parameter 'path' has schema constraints but no description. The tool description does not add any meaning about path format (absolute/relative, extension), leaving the agent without helpful guidance.

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?

Tautological: description restates name/title.

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 create_database to make a new one' for non-existent files, providing clear when-to-use guidance. However, no mention of when to use versus other tools like list_databases.

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