get_instance

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

No annotations provided, so description carries full burden. It declares the tool is read-only, specifies error conditions (instance_id not found or belongs to another account), and lists returned fields. This is strong transparency for a read 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?

Two sentences: first states purpose and output fields, second provides usage guidance. No fluff, front-loaded, every sentence 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?

For a simple read operation with one parameter and no output schema, description covers purpose, usage context, behavioral constraints, and error cases. Could mention return type (single object), but current coverage is sufficient.

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 one parameter (instance_id) with 100% schema coverage (description: 'UUID of the instance (from list_instances)'). Description adds error context but no additional semantic details beyond schema. Baseline 3 is appropriate.

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?

Description clearly states 'Get full metadata for a specific cache instance' and enumerates the fields returned (name, tier, status, etc.), establishing a specific verb-resource combination. It distinguishes itself from sibling tools like 'get_connection_string' and 'list_instances'.

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 advises to 'call list_instances first to discover valid UUIDs' and directs users to 'use get_connection_string instead if you only need the redis:// URL', providing clear when-to-use and when-not-to-use guidance.

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