ppsspp_read16

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

Discloses no side effects ('pure read'), error condition ('Returns an error if address+2 exceeds valid memory region'), endianness ('PSP is little-endian'), and return format ('Single line 'ADDR_HEX: VAL_DEC (0xVAL_HEX)''). With no annotations, the description fully addresses behavioral traits.

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 with clear section headers (PURPOSE, USAGE, BEHAVIOR, RETURNS). Every sentence adds unique value, and there is no redundancy or unnecessary text.

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 simple one-parameter read tool with no output schema, the description covers behavior, errors, endianness, return format, and memory layout hints. It is fully complete for an AI agent to select and use the tool correctly.

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 100% and includes memory layout details. The description adds extra context by reiterating endianness and return format, which enhances understanding beyond the schema. However, the schema already provides substantial information, so a baseline of 3 is appropriate; the extra value justifies a 4.

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 reads an unsigned 16-bit little-endian value from PSP memory at a given physical address. It uses a specific verb ('read'), resource ('PSP memory'), and data type, and distinguishes from siblings by naming alternative tools for different sizes.

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?

Explicitly says 'Use for 16-bit game-state fields' and provides direct alternatives: 'For single bytes use ppsspp_read8; for 32-bit use ppsspp_read32; for arbitrary byte spans use ppsspp_read_range.' This clearly indicates when to use this tool versus others.

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