application_env_patch

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

With no annotations, the description carries the full burden and delivers real value: it discloses merge-not-replace semantics, a mandatory two-phase dry-run/revision workflow, a hard refusal case ('Complex multiline documents are refused'), and a concurrency limitation. It omits auth/permission requirements and whether changes are reversible.

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 dense sentences with the operation stated first, the workflow second, and the two constraints last. No filler, every clause carries actionable information.

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?

There is no output schema, and the description covers the key return dependency ('returned revision'), so an agent can complete the typical workflow. Minor incompleteness: no statement of what the response contains beyond revision or what error states look like.

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 0%, so the description must compensate. It explains the semantics of dry_run and revision well (dry-run gating and revision round-trip), but says nothing about application_id, nor about the set/remove shape and whether removal is key-name based. Partial compensation for an undocumented 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 specific verb and resource ('Patch runtime variables') plus the merge scope ('preserving other keys and build settings'), so the agent knows exactly what is modified and what is left intact. No sibling tool overlaps this operation, so no sibling differentiation is required.

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 a concrete operating procedure ('First dry_run=true, then supply returned revision with dry_run=false') and a when-not caveat ('Not an atomic concurrency lock'). It does not name an alternative tool to use for atomic/concurrent updates, which is the only gap.

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