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

Annotations already communicate read-only and idempotent behavior, and the description adds useful context: it 'does not fetch live data or change accounts' and returns 'bundled reference material, optionally filtered or calculated from inputs.' This goes beyond the structured hints without contradicting them.

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 dense but each sentence earns its place: when to use, what content is returned, and behavioral limitations. It front-loads the usage trigger and avoids filler or repetition.

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?

With one optional enum parameter, rich annotations, and an output schema, the description fully covers what the agent needs: the use case, the scope of content, the output nature, and the lack of live data access or side effects. Nothing essential is missing.

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 covers the single optional topic parameter at 100%, including an enum and instructions to omit for all topics. The description reinforces the topics in prose but does not add new parameter-level meaning, so the baseline of 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 clearly identifies the tool as the one for explaining Canadian credit mechanics, with specific verbs like 'Use this for a requested explanation' and a detailed list of covered topics. It does not explicitly name or contrast sibling tools such as explain_when_issuers_report or describe_credit_gps, so it stops just short of full differentiation.

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 first sentence gives a direct usage condition: use it for requested explanations of Canadian credit scores, reports, utilization, or reporting timing. It does not list exclusions or explicitly name alternatives, but the context is clear enough for an agent to select it from the sibling set.

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