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

Annotations declare destructiveHint=true; the description goes beyond that by disclosing the safety carve-outs (no shell startup files, LaunchAgents, git hooks, AI-client configs, credential paths) and the recovery guarantee that overwrites keep a prior version and report its location via `previous_version`. That is exactly the context a destructive write tool needs, though rate limits or failure modes are unaddressed.

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 with the core verb and resource, then the format routing, then the security exclusions and overwrite semantics. Dense but every sentence carries information; the format enumeration and the sibling parenthetical overlap slightly, which keeps it from a 5.

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 destructive, open-world=false write with a full output schema and complete parameter documentation, the description supplies everything missing: allowed scope, forbidden targets, append vs overwrite semantics, and backup behavior. Return-value detail is already covered by the output schema.

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 100%, so the baseline is 3; the description earns an increment by tying `append=true` to adding to the end and by explaining the consequence of the default overwrite path (prior version preserved, path returned as `previous_version`). It also implicitly reinforces that missing parent folders are auto-created rather than erroring.

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 ('Writes text to a local file') plus the three modes (create, overwrite, append) and the supported file classes. It explicitly routes document formats to siblings (word_create, excel_create, ppt_create), so an agent can distinguish it without opening a schema.

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?

Names the alternatives and the condition that selects them: plain text/code files here, Word/Excel/PowerPoint via word_create/excel_create/ppt_create. It also declares the write-scope policy up front (two exception categories), so the agent knows when this tool is not permitted.

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