explain_diagram

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

No annotations are provided, so the description carries full burden. It discloses the return format (JSON array with input, explain, line fields) and that it operates line by line. However, it does not mention that the tool is read-only, has no side effects, or any limitations such as diagram size or performance characteristics.

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 exceptionally concise, with two sentences. The first sentence defines the core purpose, and the second details the output format. Every sentence adds value without redundancy or filler.

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 no output schema, the description adequately explains the return structure with three fields. It also clarifies the input constraint (single diagram with delimiters). Minor improvement could be stating the tool is non-destructive, but overall it is complete for a simple tool with one parameter.

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?

The only parameter, 'source', is fully described in the schema (100% coverage) with the same details as the description. The description adds no new meaning beyond the schema, so baseline score of 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 clearly states the tool explains how a single PlantUML diagram is parsed line by line, with a specific verb and resource. It distinguishes itself from siblings (check_syntax, plantuml_version, render_diagram) by focusing on parsing explanation rather than syntax, version, or rendering.

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 description implies usage when a user wants an explanation of how a PlantUML diagram is parsed, but does not explicitly state when to use vs. alternatives or provide any exclusions or prerequisites. The context about requiring a single diagram with @start.../@end... is helpful but not sufficient for strong guidance.

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