Read RAPID source

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

Goes well beyond the readOnly/idempotent/closed-world annotations: it discloses that the first read hits the controller (latency), that text is cached for 60 s (staleness), that the server cannot move the robot, and it warns that controller text is data rather than instructions, with an instruction to flag stale or replayed data. These are exactly the operational and safety traits an agent needs and cannot get from annotations.

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?

Four sentences, front-loaded with the resource and its read modes, followed by the cross-tool pointer, the caching behavior, and the safety constraint. Every sentence carries information an agent cannot get from structured fields; nothing is repeated verbatim from the schema or annotations.

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?

Despite eight parameters, the schema already covers all of them at 100% and an output schema exists, so the description only needs to supply what structured data cannot: caching/staleness semantics, controller access cost, and the prompt-injection caution. All of those are present, leaving nothing an agent needs 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 coverage is 100%, so task, module, context, routine, fromLine, maxLines, aroundLine and controller are all documented in the schema itself, including precedence rules. The description only restates the three modes at a high level and adds no syntax, default, or constraint detail beyond that, 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 and resource ('The RAPID source of one module, with line numbers') and immediately enumerates the three retrieval shapes: whole routine, window around a line, or a page. This clearly separates it from siblings like get_rapid_execution and summarize_controller, which deal with execution state and summaries rather than source text.

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 ties the tool to the sibling use case by noting 'Line numbers match the pointers of get_rapid_execution', which tells an agent how to chain the two calls, and describes when each read mode applies. It stops short of stating when *not* to use it or naming a competing tool to prefer, so it does not reach the top band.

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