gb_decode_cart_header

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

No annotations are present, so the description carries the full disclosure burden. It does a solid job: it reveals that the tool validates the Nintendo logo, recomputes the boot-ROM checksum, and that a mismatch means the ROM will not run—genuinely useful behavioral context. It stops short of describing error behavior (e.g., what happens with malformed hex or a failed checksum), but for a read-only decode tool this is a modest gap.

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 two tight paragraphs: one line declaring the purpose, one enriching it with concrete verification details. Every sentence earns its place, and the purpose is front-loaded. No 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?

For a single-parameter tool with no output schema and no annotations, the description explains what happens during decoding and what the checksum consequence is, but it does not describe the return shape or failure modes. An agent cannot tell whether the tool returns structured fields, a pass/fail flag, or both. Since this information is not carried anywhere else, there is a noticeable completeness gap.

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 parameter well (hex bytes, two acceptable input shapes: 80 header bytes or the first $150). The description adds little beyond 'real header' and verification semantics, so it does not meaningfully extend the schema. With 100% schema coverage, 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 states a specific verb and resource: 'Decode a real cartridge header and verify its checksum.' It further enumerates the actions (resolving codes, checking the Nintendo logo, recomputing the boot-ROM checksum), which clearly distinguishes it from siblings like gb_cartridge_header (likely a reference/spec) and gb_lookup_cart_code (single-code lookup). It does not explicitly name a sibling it is not, which keeps it from a 5.

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 implies when to use the tool: when you have actual cartridge-header bytes to decode and verify ('a real cartridge header'). The input schema adds the exact allowed shapes. However, it never says when-not to use it or which sibling to prefer for spec lookups or individual code resolution, so usage context is implied rather than explicit.

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