ppsspp_hold_buttons

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

Annotations only mark it non-read-only and non-idempotent; the description adds the crucial state-machine semantics: the held state persists across calls until the next hold_buttons call, and must be explicitly cleared with an empty combination. It also warns that send_analog does not clear buttons, which prevents a realistic misuse. This is substantive behavior beyond the structured fields.

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 PURPOSE/USAGE/BEHAVIOR/RETURNS labeling front-loads the essential fact (persistent hold) and makes scanning easy. It is slightly redundant with the 100%-covered schema, listing valid button names twice across description and schema.

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 2-parameter state-mutation tool, the definition covers required inputs, the full button vocabulary, persistence semantics, and the release path, and return values are captured by the output schema plus the brief RETURNS line. Nothing needed to invoke this correctly 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%, so both parameters and the pipe-separated name list are already documented in the schema. The description repeats the same format guidance and valid name list rather than adding new semantics, so the baseline 3 applies.

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?

States a specific verb+resource ('Hold a combination of PSP buttons') and scope ('until a subsequent call changes the state'), which is far more specific than a tautology. It distinguishes itself from send_analog ('send_analog does NOT release buttons'), but does not directly contrast itself with the closest sibling, ppsspp_press_button (momentary vs. persistent hold) — that contrast appears only in the schema, not the description.

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?

Gives clear context for when to use it (persistent held state), how to release it (call with buttons=''), and an explicit exclusion (send_analog does not release buttons). It stops short of naming press_button as the alternative for one-shot presses in the description text, leaving part of the routing to the schema.

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