read_file

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states the tool reads text, rejects binaries, and hints at size limits, but does not mention error handling for missing files or default behavior for parameters like line ranges. The description adds some context beyond the schema but not enough for full transparency.

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 extremely concise: two sentences, no wasted words. The purpose is front-loaded in the first sentence. Every sentence adds value, making it efficient for an AI agent to process.

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?

Given the tool's simplicity, the description is largely complete. It covers the key behavioral constraints (text only, size limit, rejection of binaries). It does not explain the line range feature in detail, but the schema already covers that. Without an output schema, the description could hint at return format, but it's not essential for a read operation.

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%, so each parameter already has a description. The description adds no new meaning to the parameters beyond what the schema provides. For example, it mentions 'size limit' but the schema already describes maxBytes. Baseline score of 3 is appropriate.

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's purpose: 'Read the text contents of a file.' It specifies it only works for text files within a size limit, distinguishing it from potential sibling tools that might handle binary files. The verb 'Read' and resource 'file' are specific.

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 usage conditions: 'Only works for text files within the size limit. Binary files ... will be rejected.' This tells the agent when to use the tool (text files) and when not to (binary files), though it does not explicitly suggest alternatives for binary files.

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