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

With no annotations, the description carries the full burden and does disclose key traits: the operation overwrites ('replace'), intermediate folders are created implicitly, and there is a 25 MB payload ceiling. It does not mention permission requirements, whether a prior file version is recoverable, or what is returned after a successful write.

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?

Three short sentences, front-loaded with verb, resource and allowed roots, then the example, then the payload rules. No filler and no repetition of the title.

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 mutating file-write tool with no annotations and no output schema, the description covers scope, path rules, payload formats and limits. The remaining gap is the post-write contract — what the tool returns or how to verify the result — which an agent would otherwise have to discover.

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 60% and the two undocumented parameters (content, content_base64) are precisely the ones the description explains, including mutual exclusivity of text vs binary and the size limit. It adds little for site/token, but those are already described in 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?

States a concrete verb pair ('Create or replace') plus the resource ('a file') and bounds the write to three top-level directories, with a concrete example path. This is unmistakably distinct from siblings like read_files and delete_file without needing to name them.

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 clear operative guidance on which parameter to use (content for text, content_base64 for binary) and the 25 MB cap, plus the note that folders are auto-created. It stops short of explicit exclusions or naming an alternative tool (e.g., when to prefer run_wp_cli for file changes).

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