ppsspp_evaluate

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the description's 'READ-ONLY' label mostly repeats structured data. However, 'Pauses/resumes the CPU internally' adds a meaningful behavioral side effect beyond the annotations exceptional. This helps an agent understand why a seemingly safe read may still briefly affect execution state.

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 compact and well-organized into PURPOSE, USAGE, BEHAVIOR, and RETURNS. Every line carries meaningful operational information without redundancy or fluff. The most important constraints are front-loaded.

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?

Given the two parameters, high schema coverage, and rich annotations, the description provides everything needed to invoke the tool correctly: purpose, required inputs, a behavioral side effect, an alternative for an unsupported use case, and the return shape. 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?

Schema description coverage is 100%, and the expression parameter already documents supported syntax, examples, and the no-dereference caveat. The description's 'session_id + expression' adds no new semantic value beyond the schema. There is no coverage gap for the description to compensate for, so 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 opens with a specific verb and resource: 'Evaluate a debugger expression', and enumerates the accepted operand classes ('register names, hex literals, simple arithmetic'). It also separates itself from memory-reading tools by explicitly stating dereference syntax is not supported and pointing to read_u32 instead.

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 'USAGE' line indicates that session_id and expression are required. More importantly, the exclusion 'No '*addr' dereference syntax — read memory with read_u32 instead' gives an explicit when-not-to-use rule and names the alternative. It does not cover all possible alternatives among the many sibling tools, but the key routing edge case is handled.

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