readFile

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

Discloses that it returns raw content as a single text block, throws errors on missing/unreadable files, and blocks sensitive paths. Lacks details on file size limits or behavior for binary files. No annotations provided, so description carries full burden.

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?

Four concise sentences front-loaded with purpose and use cases. Every sentence adds value without redundancy. Efficiently structured.

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 file read tool, the description covers all essential aspects: purpose, usage, output format, error conditions, and blocked paths. No output schema exists, but return value is described. Lacks only minor details like encoding confirmation, but 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 coverage is 100% for the 'path' parameter. The description adds valuable guidance: relative path resolution, null byte prohibition, and examples, exceeding the schema's basic description.

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 verb (read), resource (file), and output format (UTF-8 text). It distinguishes from sibling tools like writeFile and deleteFile, indicating a read-only operation.

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?

Provides clear use cases (inspect configuration files, source code, logs) and notes blocked paths for sensitive directories. Does not explicitly mention when not to use, but usage context is well-defined.

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