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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and a closed-world scope, so the safety profile is fully covered. The description adds that the payload contains bundled rules plus official source metadata, which is useful content context beyond annotations, but it says nothing about size, pagination, or behavior on an unknown credit. A 3 is appropriate given annotations carry the safety burden and an output schema exists.

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 efficient sentence with the resource named up front and the scope qualifier at the end. Nothing is wasted, though the terseness comes at the cost of the missing usage and parameter detail noted elsewhere.

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?

An output schema and rich annotations relieve the description of explaining return shape and safety, and it briefly characterizes the payload. However, for a lookup tool that sits between list_rule_packs and calculate_tax_credit, it omits the identifier format and the routing guidance an agent needs to call it correctly on the first try.

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 single required parameter has 0% schema description coverage, so the description must supply its meaning. "for one credit" only weakly ties the parameter to a credit identifier and gives no hint about expected format (slug, code, or display name) or whether it must come from list_rule_packs. This is a real gap for the only input.

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 gives a specific verb and resource ("Return the bundled rules and official source metadata") scoped to "one credit", which distinguishes it from list_rule_packs by implying a single-record fetch. It does not explicitly contrast with the sibling, but the singular scope makes the distinction inferable.

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?

There is no when-to-use guidance, no mention of when not to use it, and no reference to the obvious alternatives (list_rule_packs for enumeration, calculate_tax_credit for computation). The agent must infer that this is a lookup step preceding calculation or verification.

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