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

Goes well beyond annotations: discloses that 301 is served uncached so every click is counted and edits take effect, that the on-domain address goes live within a minute or two (or at publish), that WhatsApp ignores URL tags so a ref is appended to prefill_text, and that phone defaults to the business number and must never be invented. Rich operational context for a mutation tool.

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?

Dense but front-loaded: the core (what a tracked link is) comes first, followed by destination kinds, tracking, status, and lifecycle. Long single paragraph is efficient though packed; every sentence carries operational detail.

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 13-param nested-object mutation tool, the description covers destination kinds, tracking, status, expiry/fallback, prefill, and live timing. With no output schema, it does not describe what is returned (e.g. the created link and short URL), which is the main remaining gap.

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 85%, so most params are documented, but the description still adds real meaning: destination.kind semantics (email requires email, page is a site path, web is full https), tracking tags behavior on page/web vs. WhatsApp, and status default logic. It does not cover every param (e.g. forward_query, tag_destination, user_goal) but adds value above 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?

Specific verb and resource: 'Create a tracked link' with a precise definition (on-domain address plus short address sending visitors to `destination` and counting clicks). It clearly distinguishes from siblings like add_redirects, suggest_link, and create_client_connect_link by describing both the on-domain path and short link behavior.

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?

Explains conditions well: path is optional, status is 301 unless the user asks for temporary, expires_at pairs with fallback_url, and 'The path must not be a page, a redirect or another link' clarifies exclusion. It stops short of explicitly naming sibling alternatives (e.g. add_redirects vs. this tool) for an agent choosing between tools.

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