format_document

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

With no annotations, the description carries the burden of disclosing side effects. It explicitly states 'write the result to disk' and notes that includeContent returns the formatted text. This covers the mutation behavior and optional return, though it doesn't detail error handling or overwrite semantics.

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?

Two sentences, front-loaded with the action, and no extraneous details. Every word earns its place.

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?

The tool has a complex nested options object and no output schema, but the description clearly explains the primary side effect (writing to disk) and the optional return behavior. It lacks details on edge cases or option usage, but the schema covers those, making this adequate for a formatting tool.

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%, and the description only paraphrases the includeContent parameter ('Pass includeContent to also get the formatted text back') without adding new details about file or options. It adds minimal value beyond the schema, so the 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 clearly states the action: 'Format a TypeScript/JavaScript file using TypeScript's built-in formatter and write the result to disk.' It identifies the resource (file) and the specific verb (format), and distinguishes itself from sibling analysis tools by being the only formatting 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?

The description implies when to use the tool (for formatting) but does not explicitly contrast it with alternatives or state when not to use it. Siblings are all read/analysis tools, so the purpose alone suggests usage, but no direct guidance is provided.

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