plan_diagram

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

With no annotations, the description carries the full burden and discloses the key behavioral traits: it computes ranks/rows, routes edges through corridors, places guard labels, and preserves manual overrides (explicit x/y and edge waypoints). The override-preservation note is genuinely useful non-obvious behavior. It omits output format and error handling, but the core mutation/computation behavior is transparent.

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?

A single well-structured sentence, front-loaded with the phase and core action, then detail. It packs ranks/rows, routing, guard-label placement, and manual-override behavior without bloat — efficient but slightly dense in the middle.

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 1-parameter tool with no output schema, the description covers input provenance and behavior well. However, since no output schema exists, the description arguably should describe the return value (the positioned layout structure) and error behavior on invalid specs, which it does not.

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% for the single 'spec' parameter, so baseline is 3. The description adds value by naming the spec's source (analyze_requirement) and elaborating on what the layout computation entails, but it doesn't add format or structural constraints beyond what the schema documents.

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 ('computes') and resource ('a concrete, positioned layout'), and anchors itself as 'PHASE 2 of diagram generation,' which positions it in a pipeline and distinguishes it from siblings like analyze_requirement and design_diagram. An agent can tell exactly what this step does.

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?

'Takes the analysis (or any IR spec)' clearly tells the agent what input to feed it and that it follows analyze_requirement in the pipeline. The phase framing implies sequencing, but no alternative tools are explicitly named nor exclusions stated, so a point is lost.

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