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

Annotations already carry readOnlyHint/openWorldHint/idempotentHint, so safety is covered; the description's 'Read-only.' is redundant but harmless. It adds genuine behavioral context beyond the annotations: minimum bids vary by country/currency/targeting and sub-floor bids cause non-delivery or rejection, specifically on TRY accounts with generic defaults. It does not mention rate limits or latency, so it falls just short of the top band.

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?

Front-loaded with the core action and output, followed by a compact rationale and a parameter glossary. The 'Why it matters' paragraph is longer than strictly necessary but earns its place by justifying the call ordering; no filler sentences.

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 an output schema present, the description needn't explain return values, and it still names the key returned number. Combined with the pre-call ordering guidance and failure-mode context, this is nearly complete; only language and objective_type remain undocumented for a 7-parameter tool.

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 0%, so the description must compensate and it only partly does: it defines campaign_type values (TEXT_AD | SPONSORED_UPDATES | SPONSORED_INMAILS | DYNAMIC), bid_type values (CPC | CPM | CPV), and the geo_urns format plus the empty-string default meaning. account_id, language, and objective_type go unexplained in both description and 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?

States a specific verb and resource ('asks LinkedIn what it actually costs to advertise to a given audience') and enumerates the concrete outputs: suggested bid, allowed floor/ceiling in account currency, and minimum daily budget. It is clearly distinct from siblings like create_linkedin_campaign (which consumes it) and linkedin_audience_forecast.

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 an explicit ordering rule — 'Run this BEFORE create_linkedin_campaign and use the returned number as unit_cost' — and names linkedin_targeting_search as the upstream source for geo_urns. Both when-to-use and the dependency chain are spelled out.

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