build_html_report

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

With no annotations, the description carries the behavioral burden. It discloses the primary side effect—writing an HTML file, with auto-generation when output_filename is empty—and states the return value as the relative path to the saved file. It does not mention overwrite behavior or failure handling for missing chart paths, but it is substantially transparent for a report-builder tool.

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 compact and front-loaded: a one-sentence purpose, a one-sentence workflow instruction, and a tight Args list with no redundant prose. Every line contributes necessary information, and the return value is stated briefly.

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 seven parameters and no annotations, the description covers all parameter semantics, the sequencing requirement, the output behavior, and the return path. The workflow context ('after all chart tools have been run') is sufficient for an agent to invoke it correctly. Minor edge-case constraints are not documented, but the description is complete enough for correct usage.

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?

Input schema coverage is 0%, so the description must carry parameter meaning, and it does: each argument receives a role, such as 'Title shown on the cover page' and 'one per chart, same order as chart_paths.' The repeated 'same order' instruction is particularly useful. Constraints like equal-length arrays are implicit rather than explicit, but the semantic roles are clear.

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 a specific verb and resource: 'Render an HTML summary report from a set of pre-generated charts.' This clearly distinguishes it from sibling chart-generation tools, which produce charts, and from export_pdf_report, which exports a PDF. The prerequisite of 'pre-generated charts' also scopes the tool's role precisely.

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 gives an explicit trigger condition: 'Call this after all chart tools have been run and you have collected their output paths.' This tells an agent exactly when in the workflow to invoke the tool. It does not explicitly name alternatives or state when HTML is preferred over the sibling PDF export, so it lacks explicit exclusions.

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