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

Annotations already declare readOnly/idempotent/non-destructive/closed-world, so the safety profile is covered. The description adds real value beyond that: the rationale (ordering would mean spending money), and the fact that audience estimation is intentionally out of scope. It does not cover pagination or rate limits.

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?

Well front-loaded: purpose first, then the two modes, then the boundaries. Slightly dense in the campaign-card enumeration (views, answers, conversion, timings, socdem, payment), but every element describes a return field that matters given there is no output schema.

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 carries the full burden of describing returns, and it does so for both branches — list fields (price per answer, minimum group size) and card fields (status, moderation, views, answers, conversion, first/last completion, average time, socdem, payment). Nothing essential to calling it correctly is missing.

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% and both parameters are documented in the schema, including the 'without it you get the list' behavior of campaign_id. The description's mode split reinforces but does not add syntax or constraints beyond what the schema already provides, so the baseline 3 applies.

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 resource (respondent campaigns / purchased survey completions) and spells out both operating modes: list-of-campaigns without campaign_id, detailed campaign card with campaign_id. No sibling in the list does anything similar, so the agent can distinguish it immediately.

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?

Explicitly bounds the tool: read-only, ordering and paying for a campaign cannot be done through the assistant, and the available-audience-by-socdem calculation is done in the cabinet. This tells the agent when NOT to reach for it, though it does not name a specific alternative tool to use instead.

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