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

With no annotations, the description must fully disclose behavior. It states 'Return,' implying a read-only operation, but lacks details on side effects, authorization needs, rate limits, or error handling (e.g., invalid credit). Minimal transparency.

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 a single sentence with no fluff, achieving conciseness. However, it is too brief to be adequately structured; it could be rephrased to front-load the key action while adding brief parameter context.

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?

Despite having an output schema, the description does not elaborate on return content (e.g., rule structure or metadata fields). With one parameter, the description should minimally explain the parameter's role, which it fails to do, making the tool incomplete for reliable agent use.

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 0%, and the tool description does not explain the 'credit' parameter beyond its name. The agent has no indication of whether credit is an ID, name, or code, nor any format constraints. This is a critical gap for correct usage.

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 clearly states the tool returns 'bundled rules and official source metadata for one credit,' with a specific verb and resource. This purpose distinguishes it from siblings like list_rule_packs (which likely returns multiple credits) and calculate_tax_credit (which involves computation).

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?

No guidance on when to use this tool versus other siblings. The description does not mention scenarios, prerequisites, or alternatives (e.g., 'use list_rule_packs to see all credits'). This leaves the agent without context for appropriate invocation.

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