vault_write

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

Annotations already declare destructiveHint, idempotentHint, and readOnlyHint=false, so the safety profile is covered. The description adds real value beyond them: parent directories are created, binary/NUL content is refused, there is no automatic retry, and no force-override exists for existing files. It stops short of noting permission/auth requirements or rate limits.

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?

Four terse clauses, front-loaded with the core action before constraints. Every sentence carries a distinct behavioral fact with no filler.

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?

An output schema exists, so return values need not be described. For a mutating tool the description covers the crucial mechanics (ifMatch gating, parent creation, refusal rules, retry behavior), leaving only path semantics and content limits unaddressed.

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 0%, so the description must carry the load. It meaningfully explains ifMatch's purpose (required for existing files, no force bypass), but says nothing about path format constraints or the content size limit that the schema enforces. It compensates for one of three parameters only.

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+resource ('Create or replace UTF-8 text'), which is far more precise than the bare name vault_write. It implicitly differentiates from siblings vault_append/vault_patch by emphasizing replace semantics, though it never names them explicitly.

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?

It gives a conditional rule ('Existing files require ifMatch; no force bypass') which implies when the tool is applicable, but never states when to choose it over vault_append or vault_patch, nor what happens on a first-time create vs overwrite beyond the ifMatch hint. Usage is implied rather than explicit.

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