get_ec2_instance

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

No annotations are present, so the description alone must carry the burden. 'Get' strongly implies a read-only operation, and the attribute of the resource as a specific EC2 instance sets a clear boundary. It doesn't detail error behavior or the exact returned fields, but this is minor for such a straightforward retrieval 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?

A single sentence, front-loaded with the action and containing zero filler words. Every part of it earns its place.

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 tool with one required parameter and no output schema, the description is largely complete: the agent knows the exact input and the general outcome. It doesn't explicitly state that the operation is read-only or list the return fields, but neither gap severely undermines an agent's ability to invoke it 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 schema already documents the single parameter with a clear description and an example, giving 100% parameter coverage. The description repeats that the instance ID is the lookup key but adds no new semantics beyond the 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?

The description identifies a specific verb ('Get'), a concrete resource ('detailed information about a specific EC2 instance'), and the selection criterion (instance ID). It does not explicitly name a sibling like get_ec2_instances, but the word 'specific' against the plural sibling still supplies a strong distinction.

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 phrase 'by its instance ID' makes the usage context clear: use this when you already have a known instance ID and need details for that one instance. It does not explicitly list alternatives or when-not-to-use, but for a one-parameter read tool this is adequate.

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