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

Annotations already declare destructiveHint=true and readOnlyHint=false. The description adds valuable behavioral detail: the deletion is permanent and results in a 'not found' response for subsequent accesses. It also instructs to confirm with the user, which is a meaningful operational trait. It does not contradict the idempotentHint=true annotation, though it does not elaborate on idempotency.

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?

Two sentences convey the action, the consequence, and a user-confirmation requirement with no filler. The key information is front-loaded, making it easy for an agent to parse quickly.

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 simple one-parameter destructive tool with annotations covering safety (destructiveHint, readOnlyHint) and an idempotentHint, the description covers the essential semantics. It could mention what happens when the link doesn't exist, but that is not critical given the idempotentHint. The confirmation instruction is an important operational detail not in annotations.

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?

The input schema fully documents the 'code' parameter with a pattern and description, giving 100% coverage. The tool description does not add any additional parameter meaning, so it meets the baseline of 3 but does not exceed it.

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?

The description states the action ('Delete a link permanently') and the consequence ('Anyone opening it afterwards gets 'not found'') with a specific verb and resource. It clearly distinguishes from siblings like update_link or get_link, as it is the only destruction tool.

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?

The description gives clear when-to-use context (deleting a link) and adds a specific guideline: 'Confirm with the user first.' It does not explicitly mention alternatives or exclusions, but the tool's unique purpose among siblings makes the usage obvious. A 5 would require naming a sibling or an explicit 'use X instead' clause.

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