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

Annotations already declare read-only, idempotent, non-destructive, so the safety bar is low; the description still earns credit by disclosing that bot/crawler hits are excluded and surfaced separately as bot_hits, and that campaign-tagged links report form-lead attribution. That is real behavioral context an agent could not infer from the schema or annotations.

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 core scope and the metric list are front-loaded in one sentence, with the default window stated separately at the end. The metric enumeration makes the sentence long and dash-laden, but every clause carries information.

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 rightly describes what comes back (totals, uniques, per-day, referrers, countries, devices, tagged-lead counts, bot_hits), which is exactly the missing information. The undocumented user_goal parameter and vague 'days' bounds keep it short of complete.

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 only 50%, but the description compensates: it explains link_id's meaning and provenance ('from list_links', omitted = all links) and gives days a default of 30. It leaves user_goal and the days upper bound unaddressed, so it does not fully close the gap.

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 specific verb and resource ('Clicks on one tracked link ... or on all of them') and enumerates the exact metrics returned, so an agent knows precisely what this tool produces. It also disambiguates the resource by pointing to list_links for link_id, setting it apart from sibling list/update link tools.

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 tells the agent how to scope the call (pass link_id from list_links, or omit it for all links) and gives the default 30-day window. It never says when to prefer this over analytics siblings such as get_campaign_performance or get_preview_stats, so the routing decision is only implied.

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