chmod_calc

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

With no annotations, the description must communicate the tool's side-effect profile. 'Convert' implies a pure, non-destructive calculation rather than a filesystem chmod operation, and the bidirectional example clarifies the transformation. However, it does not address behavior for invalid or ambiguous inputs (e.g. 'u+x' or partial modes).

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 core description is a single concise sentence with a helpful example, but it is prefixed by '[PRO — 3 trial uses left]', which is unrelated to the tool's semantics. Apart from that small bit of noise, the structure is efficient.

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 pure conversion utility, the combination of description and schema fully specifies what the agent needs for invocation: the accepted input format(s) and the conversion action. The output is inferred from the bidirectional arrow; no output schema exists, but the result is obvious. Edge cases like special mode bits are not covered, but they are unlikely to be required for normal selection.

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?

The input schema already documents the single 'permission' parameter with 100% coverage, so the description adds only the bidirectional conversion example and Unix context. This is a small increment over the schema's 'Numeric ... or symbolic ...' explanation.

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 uses a specific verb ('Convert') with a clear resource ('numeric and symbolic Unix file permissions') and a concrete bidirectional example ('755 ↔ rwxr-xr-x'). It unambiguously identifies the tool's function and differentiates it from sibling utility tools like number_base or color_convert.

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 statement 'Convert between numeric and symbolic Unix file permissions' establishes a clear use case: whenever a user needs to translate between these two representation formats. It does not explicitly name alternatives or exclusions, but the tool's unique function among the siblings makes this sufficient.

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