Read File

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

Annotations already provide readOnlyHint=true and destructiveHint=false, so the safety profile is known. The description adds useful behavioral context about supported formats (PDF, DOCX, PPTX, plain text) and truncation behavior ('Long files are truncated to max_chars'), which goes beyond what annotations state and helps set expectations.

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?

Three succinct sentences deliver the core purpose, supported formats, source of ids, and truncation limit. Every sentence earns its place, and the description is front-loaded with the primary action and outcome.

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 straightforward read tool with strong annotations and an existing output schema, the description covers the essential operational details: file types, id sourcing, and truncation. Minor gaps include error handling or exact return format, but these are adequately compensated by the schema and annotations.

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 description coverage is 100%, with both file_id and max_chars already documented. The description reinforces the source of file_id (from list_files) and the role of max_chars in truncation, but does not significantly enhance the schema's clarity. Baseline 3 is appropriate when the schema already carries the semantic load.

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 uses a specific verb ('Download') and clearly states the resource ('Canvas file') and the outcome ('return its text'). It lists example content types (lecture slides, notes, readings) and distinguishes itself from siblings like list_files and get_page by focusing on file content extraction.

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 clearly indicates a prerequisite: get file ids from list_files or course_content, which tells the agent when to use this tool. It does not explicitly mention alternatives or exclusions, but the context is specific enough for effective selection among sibling reading tools.

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