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

The description adds substantial behavioral detail beyond the readOnly/destructive annotations: campaign parents collapse into single rows, totals are aggregated, assistant links are included and flagged readOnly=true, and pagination is over groups rather than documents. This gives an agent an accurate model of what the tool actually returns and what to avoid doing with read-only rows.

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?

The description is dense but every sentence earns its place: purpose, distinguishing use case, aggregation behavior, read-only caveat, filtering, and follow-up drill-down paths all appear in a logical, front-loaded order. Despite its length, there is little redundancy and no filler.

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?

With no output schema, the description fills the gap by naming the key output fields (totalClicks, linksCount, campaignsCount, canonicalId, members[]) and clarifying pagination semantics. Combined with the fully described parameters, an agent has enough context to select and invoke the tool correctly.

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 schema already documents all four parameters. The description reinforces the meaning of origin and pagination but does not add significant semantic detail beyond what the schema provides, so the baseline score of 3 is appropriate.

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: 'List short links grouped by DESTINATION URL', and immediately distinguishes itself from nevent_list_short_urls by explaining that it returns one row per destination rather than per link. This makes the tool's unique role unmistakable.

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?

It gives an explicit use case ('how much traffic is this landing page getting across all my campaigns?') and directly explains why the sibling nevent_list_short_urls cannot answer it. It also notes when assistant links are included and how to drill deeper, offering clear guidance on when to use this tool versus alternatives.

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