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

Annotations already declare readOnlyHint=false, idempotentHint=true, and destructiveHint=false; the description usefully adds the upsert semantics ('a new rule for an address already mapped replaces it'), which explains the practical consequence of an overlapping write. It does not mention permissions or validation failures, but the annotation coverage keeps the bar low.

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 tight sentences: the first states what the tool does and why, the second front-loads the replacement behavior. No filler or redundancy.

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 three-parameter mutation tool with full schema coverage and annotations covering safety and idempotency, the description supplies the missing behavioral piece (replacement of existing mappings). Return values are not explained, but no output schema exists and the tool's outcome is self-evident.

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 100% so the baseline is 3, and the description adds real meaning beyond the schema by clarifying that 'from' accepts either a full URL or a bare path. It adds nothing about productId or slug, which the schema already covers.

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 concrete verb and resource ('send an old help center address on to one of this product's articles') and scopes it to help center redirects, which is clearly distinct from siblings like remove_redirect and list_redirects. An agent knows exactly what this creates without opening the 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?

Gives clear context for use ('so old links keep working'), implying the migration/legacy-URL scenario. It does not name alternatives such as list_redirects to check existing mappings or remove_redirect to undo, so it stops short of explicit routing guidance.

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