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

Annotations already declare the safety profile (not read-only, open-world, non-idempotent, non-destructive), so the bar is lowered. The description adds meaningful context beyond them: a hard limit of 50 links, the business semantics that renters count for the partner, and the two-months-free perk. It omits any error or overflow behavior when the cap is exceeded.

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, front-loaded with the core action and the scoping limit. The second sentence leans toward marketing language ('same two-months-free perk') but still conveys useful referral semantics. No wasted verbiage overall.

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 write tool with full schema coverage and no output schema, the description supplies the missing conceptual context: what a sublink is, its scope, and its referral effect. It does not explain auth via partner_key or failure behavior, but annotations and schema cover most of the remaining ground.

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 both parameters (label, partner_key) are already documented, and the description adds no per-parameter meaning such as how partner_key is obtained or the code format. Baseline 3 is appropriate when the schema carries the parameter documentation.

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 a specific verb and resource ('Adds a tracked link with its own code') and scopes it clearly to one location, building or staff member. It is easy to distinguish from read siblings like partner_get_links or partner_list_sublinks. However, it never names an alternative tool, so it falls short of explicit sibling differentiation.

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?

There is no when-to-use guidance, no prerequisites, and no mention of alternatives such as partner_claim_key or partner_rotate_key. The '(up to 50)' note hints at a cap but does not explain what to do when it is reached, and nothing indicates when this tool should be chosen over its siblings.

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