file_read

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

With no annotations, the description discloses relevant behavioral traits: files are read in text mode with UTF-8 default, path must be absolute, and only text-based files are supported. This goes beyond the schema by stating the read mode and platform context, though it does not cover error behavior or large file handling.

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 front-loaded with the primary action in the first sentence, followed by concise usage examples, encoding behavior, and constraints. The list of file extensions is useful but lengthens the description slightly. Overall, each sentence earns its place.

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 tool with 2 params and no output schema, the description covers purpose, usage, constraints, and return value (full text). It could mention error cases or limits, but for this level of complexity it is reasonably complete.

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 coverage is 100% and both parameters have descriptions. The description repeats the absolute path requirement and UTF-8 default already in the schema. It adds the list of supported file extensions, which provides context for the path parameter, but does not materially enhance parameter understanding.

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 reads and returns full text contents of a file, with a specific verb ('Read') and resource ('file contents'). It enumerates supported file types and differentiates from siblings like file_write and file_search by focusing on reading existing text files.

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 explicit context for when to use the tool ('view configuration files, read source code, inspect log files, or extract data from files') and an explicit exclusion ('For binary files... use a different approach'). It does not name specific alternative tools but gives clear conditional guidance.

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