Galaxy Brain

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states the tool retrieves a plan by ID but doesn't explain what a 'plan' is, whether this is a read-only operation, if it requires authentication, or what happens if the ID is invalid. For a tool with no annotation coverage, this leaves critical behavioral traits unspecified.

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 very concise ('Get a plan by ID'), consisting of a single, direct sentence that front-loads the core action. It wastes no words, making it efficient for quick understanding. However, it could be slightly improved by adding minimal context without losing brevity.

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?

Given the lack of annotations and output schema, the description is incomplete. It doesn't explain what a 'plan' is in this context, what data is returned, or how errors are handled. For a tool with no structured support, the description should provide more context to ensure proper usage, but it falls short.

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 has 100% description coverage, with 'plan_id' documented as 'The plan ID'. The description adds no additional meaning beyond this, such as format examples or constraints. Since the schema does the heavy lifting, the baseline score of 3 is appropriate, as the description doesn't compensate but also doesn't detract.

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 the tool's purpose ('Get a plan by ID'), which includes a verb ('Get') and resource ('plan'), making it clear what it does. However, it doesn't distinguish this tool from sibling tools like 'list_plans' or 'generate_plan', leaving ambiguity about when to use each. The purpose is understandable but lacks specificity compared to alternatives.

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 description provides no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites, such as needing a plan ID, or compare it to siblings like 'list_plans' for browsing plans or 'generate_plan' for creating new ones. Without this context, users might misuse the tool or overlook better options.

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