analyze_chart

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

With no annotations provided, the description carries the full burden. It discloses that the question is optional and that an empty question triggers general analysis, and it clearly states it returns 'a text analysis'. It also gives examples that clarify expected behavior. It does not mention limitations such as unsupported image formats, but it covers the core behavioral traits transparently.

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 well-structured with 'Args', 'Returns', and 'Examples' sections. It is front-loaded with the core purpose, and every sentence contributes useful information without redundancy. It is appropriately sized for the tool's complexity.

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 tool with two parameters (one optional) and an output schema, the description is comprehensive. It covers purpose, parameter semantics, return type, and provides concrete examples. The output schema already exists, so the description need not detail return values, and it still gives a concise overview.

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 schema has zero description coverage, so the description must fully explain parameters. It does so effectively: image is described as 'file path, URL, or base64', and question is explained as optional with behavior defined when 'empty'. This adds significant meaning beyond the raw schema definitions.

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 'Analyze a chart, graph, diagram, or UI screenshot', using a specific verb and resource. It further distinguishes itself from siblings by specializing in 'data visualisations, technical diagrams, flowcharts, and UI screenshots where spatial layout and relationships matter', clearly differentiating it from see_image and describe_image.

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 provides strong context for appropriate use, stating it is 'Specialised for understanding data visualisations, technical diagrams, flowcharts, and UI screenshots'. However, it does not explicitly name alternative tools or state when not to use this tool, so it falls short of full explicit guidance.

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