append

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

Discloses two important failure modes beyond the basic operation: file existence and read-only restrictions. With no annotations, this adds useful behavioral context, though other potential behaviors (e.g., encoding, size limits) are omitted.

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 that are front-loaded with the core action, followed by key constraints. Every word adds value with zero redundancy.

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?

Covers the main behavior and two error scenarios, but lacks information on return values (success indicator, appended content?) and potential limitations (max file size, binary vs text). Given no output schema, some feedback on success would improve completeness.

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?

Parameters (content, path) are self-explanatory given the tool purpose, but the description adds no extra meaning beyond the schema. With 0% schema description coverage, baseline is 3; no improvement or detriment.

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?

Description specifies the action (append content), the target (existing file), and failure conditions (file missing, read-only mode). It clearly distinguishes from siblings like write_file (which can create/overwrite) and create_directory.

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?

Indicates when to use (appending to existing files) and when it fails (non-existent file, read-only), guiding against misuse. However, lacks explicit alternatives or comparison with sibling tools.

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