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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so the safety profile needs no restating. The only behavior the description adds is result ordering ('newest first'); the case-insensitive name/subject matching merely restates the `search` schema description, and pagination behavior is left unaddressed.

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 action and ordering lead the sentence with zero preamble, and the second sentence is task-focused. It is slightly padded with parenthetical example phrases, but nothing is redundant.

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 5-param, zero-required, read-only listing tool with no output schema, the agent gets action, ordering, and search strategy; pagination (page/pageSize defaults and the 100 cap) is left entirely to the schema. Adequate, with a small gap around result-set size expectations.

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 100%, so 3 is the baseline. The description goes further by explaining how to actually choose a `search` value ('try distinctive words from their description and broaden if no hits'), which is operational meaning the schema's one-line 'case-insensitive substring match' does not convey.

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?

Starts with a specific verb+resource ('List email campaigns') and adds ordering scope ('newest first'), which unambiguously places it apart from create_campaign, update_campaign, and delete_campaign. It never explicitly names a sibling it competes with (e.g. get_campaign_stats or list_automations), so it stops short of the top band.

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 concrete routing guidance for the free-text path: use `search` when the user describes a campaign vaguely, with example phrasings and a fallback ('broaden if no hits'). It does not cover tool-level alternatives (stats vs listing vs search_contacts) or when not to use this tool.

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