create_file

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

With no annotations, the description carries the full burden. It usefully discloses the non-destructive guarantee ('Never overwrites') and the analogy-generation behavior of model_from, plus the existence of verification. It does not describe required permissions, what happens to the file on failure outside the verify path, or the return shape, leaving real gaps for a write tool.

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 correctly: the core action and the never-overwrites guarantee come first, then the model_from explanation. The closing clause about the worker not needing to know conventions is somewhat rhetorical padding, but the overall size is proportionate to the tool's unusual semantics.

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 five-parameter write tool with no annotations and no output schema, the description covers the main creation and analogy flow well but leaves allow_secrets unexplained and says nothing about failure/side-effect behavior beyond verify. Adequate for the happy path, incomplete around safety-relevant parameters.

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 40%, so the description must compensate, and it does well for model_from — explaining the analogy mechanism far beyond the schema's one-liner. However, allow_secrets is left completely undocumented in both the schema and the description, which is a notable risk for a flag governing secret material, and instruction/file_path are unexplained.

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?

States a specific verb and resource ('Write a new source file') and immediately constrains it with 'Never overwrites', which separates it from the mutation-siblings like insert_symbol and fix_symbol that edit existing files. It never names those siblings explicitly, so the distinction must be inferred rather than read.

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?

Gives strong conditional guidance for one path ('where a codebase already has many files of one kind', use model_from), but says nothing about when to reach for create_file versus insert_symbol or fix_symbol for the same file, and gives no prerequisites or ordering advice. Usage context is implied by the never-overwrites constraint rather than stated.

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