append_to_file

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

No annotations are provided, so the description carries the full burden. It usefully discloses 'byte concatenation' and 'Writes atomically,' which are meaningful behavioral traits. However, it does not mention whether the file must already exist, is created if missing, or what errors/return values to expect.

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 extremely concise, with the core purpose front-loaded in the first phrase and only essential additional details (atomic writes, optional newline). No filler or redundant explanations.

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?

Given the rich schema and simple append operation, the description covers the core behavior adequately. However, without annotations or an output schema, it leaves gaps around file creation behavior, permission requirements, and return/error semantics.

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 the baseline is 3. The description adds minimal value beyond the schema, merely highlighting 'ensure_newline_before' and atomic writes, while the schema already documents byte-for-byte writing and caller responsibility for line endings.

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 operation: appending content to the end of a file, emphasizing 'byte concatenation' to indicate raw, unmodified appending. This distinguishes it from sibling tools like prepend_to_file and insert_at, which target different positions.

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 usage is implied by the operation name and description—append when you want to add to the end of a file—but there is no explicit guidance about when to use this over prepend_to_file or insert_at, nor any exclusions or prerequisites.

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