write_file

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

No annotations are provided, so the description should disclose behavioral details. It does not state that the tool overwrites existing files by default, nor does it mention the append option, permission requirements, or the fact that createDirs can create parent directories. The only behavioral hint is 'optional encoding and directory creation,' but this is minimal and does not cover the destructive overwrite aspect.

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 a single, concise sentence with no wasted words. It communicates the core action and two optional features. However, it is too short to include important behavioral details, so while it is concise, it sacrifices completeness for brevity.

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?

This write tool has no output schema and no annotations, leaving the description as the primary source of behavioral context. It does not explain return values, overwrite semantics, append behavior, or file creation side effects. For a mutation tool with 5 parameters, the description is insufficiently complete.

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 100%, so each parameter is already documented in the input schema. The description adds marginal value by mentioning 'encoding' and 'directory creation,' but these are already covered by the schema's descriptions for 'encoding' and 'createDirs.' It does not clarify the meaning of 'append' or provide additional context beyond the schema.

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's purpose: 'Write content to file with optional encoding and directory creation.' It uses a specific verb ('write') and resource ('file'), and distinguishes itself from sibling tools like read_file, copy_file, and delete_file. However, it omits the append/overwrite distinction, which is a core behavior, so it isn't fully explicit.

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?

No guidance is provided on when to use write_file versus alternatives such as copy_file or move_file, nor are there any exclusions or prerequisites. The description does not mention that append mode can be used to add content without overwriting, or that createDirs is useful for nested paths. The tool is left to be inferred solely from its name.

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