Use an existing application for this folder

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

Annotations only declare openWorldHint=false and destructiveHint=false, so the description carries the real burden and does so: it names the file it mutates (.antideploy.json) and warns that a wrong choice overwrites live deployment state. It stops short of saying what happens if a link already exists or how failures surface, so it is strong but not exhaustive.

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 what the tool does, then the value source, then the risk. Nothing is redundant with the schema beyond a brief reinforcement of the id source, and every clause adds 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?

For a two-parameter tool with no output schema, the description covers purpose, value provenance, and the destructive downstream consequence, which is what an agent needs to call it safely. It could still state whether re-linking an already-linked folder is idempotent or an error.

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% and both parameters are described there, including the same 'An id from list_applications' hint, so most param guidance is duplicated rather than additive. The one genuinely new constraint, never guess and never take an id the user did not name, is a usage rule more than a parameter semantic.

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 pair (record an existing application in .antideploy.json for a folder) and adds the downstream effect, 'so deploys and the other tools act on it'. The wording 'the user already has' cleanly distinguishes it from create_application, and the reference to list_applications separates it from the discovery tools.

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 an explicit precondition ('Only when the user said which one; never guess') plus the exact source of the required value ('Take the id from list_applications'). It also names the consequence of violating the rule (a deploy would replace what is live), which is a true when-not condition rather than generic advice.

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