read_file

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

Annotations already declare the tool as read-only, idempotent, and non-destructive, so the bar is lower. The description adds valuable behavioral details about the max_chars limit, default value, and truncation behavior, which go beyond the annotations and help the agent understand output boundaries.

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 two sentences, front-loaded with the core purpose, and every word earns its place. It avoids fluff while including key constraints and use cases.

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 simple read-only tool with two parameters, high schema coverage, and strong annotations, the description covers the essential information: what it reads, what it returns, and size limits. It doesn't explain error cases or binary file handling, but that is not critical for this tool's complexity. The description is sufficient.

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% for both parameters, so the schema already explains path (absolute/home-relative) and max_chars (range/default). The description merely restates the default and max values without adding new semantics, so the baseline score of 3 applies.

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 ('Read') and resource ('file at the given path'), clearly stating it returns text contents. This distinguishes it well from sibling tools like read_file_lines, tail_file, and write_file, even without naming alternatives.

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 clear use-case context: 'Useful for reading config files, logs, scripts, notes, etc.' This implies when to use the tool, though it does not explicitly mention alternatives or when not to use it. Given the broad utility of a file reader, this is strong guidance.

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