local_files

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

With no annotations, the description carries the full burden of behavioral disclosure. It explicitly flags the operation as 'EXPENSIVE' and clarifies it returns full files, not line ranges. While it doesn't cover error handling or permissions, the key behavioral traits (read-only, cost, full-file scope) are disclosed meaningfully.

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 three sentences, each serving a distinct purpose: stating the core action, warning about cost, and providing usage guidance. It is concise, front-loaded, and free of filler.

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 two-parameter tool with no output schema, the description covers the core purpose, cost, and alternatives. It could detail path semantics or error scenarios, but given the simplicity, it is sufficiently complete for an agent to select and invoke correctly.

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 0% and the description does not explain the 'paths' or 'max_bytes' parameters. Although the parameter names are somewhat self-explanatory and the schema includes a default for max_bytes, the description adds no additional meaning or guidance beyond what the schema already provides.

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 full source files from disk, using the specific verb 'Read' and the resource 'full source files'. It also distinguishes itself from alternatives by noting it's for whole files only, contrasting with line-range reads from search/node results.

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?

Explicit guidance is provided: 'Prefer built-in Read with line ranges from search/node results instead' and 'Use this only when you need a whole file that search/node didn't cover.' This clearly specifies when to use and when not to use the tool, naming an alternative.

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