Get file info

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

Annotations already declare readOnlyHint=true and openWorldHint=false, but the description adds real context beyond that: performance characteristics ('very fast'), cache semantics ('cache validated by mtime+size'), and concurrency posture ('Batch-safe: yes'). The stated output field names also set expectations. It does not mention error behavior for missing paths, which keeps it at 4 rather than 5.

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?

Front-loaded with the core purpose, then organized into labeled lines (Use when / Avoid when / Speed / Output / Batch-safe) that are each one short clause. Every line carries actionable information with no 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 one-parameter read tool with no output schema, the description covers purpose, when to use, an alternative, performance, output shape, and batch safety — everything an agent needs to call it correctly and interpret the result.

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?

There is a single parameter with 100% schema description coverage, so the schema already fully documents its type and the workspace-relative/absolute semantics. The description adds no syntax or constraint detail beyond what the schema supplies, so baseline 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 names the resource and exactly what is returned (kind, size, modification time) for files or directories, and explicitly separates it from project_read_file, which is the nearest sibling an agent could confuse it with.

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?

It gives an explicit 'Use when' (only need size/mtime/kind, or checking path existence) and an explicit 'Avoid when' naming the alternative tool (project_read_file) for file contents. Nothing is left to inference.

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