gb_memory_map

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

With no annotations, the description carries the full burden of behavioral disclosure. It clearly explains the two modes: with no address, it returns the full region table, I/O ranges, and jump vectors; with an address, it reports the memory region plus conditional details like hardware register, RST/interrupt vector, cartridge-header field, and banking register (when mbc is given). This discloses what the tool does and under what conditions. However, it does not mention side effects (likely none), error handling, or the output format, which are minor gaps given the tool's read-only nature implied by 'identify.' Overall, it provides strong behavioral context.

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 concise and well-structured. It opens with a clear one-sentence purpose, then immediately explains behavior in two succinct conditional clauses. There is no redundancy or fluff; every sentence contributes to understanding the tool. The key information (what it does, what happens without an address, what happens with one, and the role of mbc) is front-loaded and logically organized.

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?

The description covers the main behaviors and output components: full region table, I/O ranges, jump vectors, hardware register, RST/interrupt vector, cartridge-header field, and banking register. Given there is no output schema, this is a good effort at explaining what the tool returns. It does not mention edge cases like invalid addresses or how the output is structured (e.g., text vs. structured data), but these are relatively minor gaps for a lookup tool. Overall, it provides sufficient context for an agent to call the tool effectively.

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 coverage is 100%—both parameters have descriptions in the schema. The description adds value beyond the schema by explaining how the 'mbc' parameter affects the output (which banking register a write would hit) and how omitting the address changes the result (returns the whole map). This enriches the semantic understanding of the parameters, even though the schema already covers their basic meaning. The description makes the interaction between parameters and output clearer, justifying a score above the baseline 3.

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's purpose: 'Identify what lives at an address, across every relevant source.' It specifies a verb (identify), a resource (address), and scope (across relevant sources). It also details the two modes (with/without address) and lists the types of information returned, which distinguishes it from sibling lookup tools like gb_lookup_register or gb_decode_cart_header that focus on specific aspects. This is a clear, specific, and differentiated purpose.

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 explains what the tool does in different scenarios (with and without an address) but does not explicitly state when to prefer this tool over alternatives. It mentions that it covers 'every relevant source,' implying it is the comprehensive choice, but it doesn't explicitly say 'for register-specific details use gb_lookup_register' or provide exclusion criteria. While an agent can infer usage context, the lack of explicit alternatives or conditions for selection leaves some ambiguity.

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