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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuine context beyond them: the breadth of the returned object and the required 'campaigns.read' scope, which an agent must know before calling. It does not cover error behavior for a missing or unauthorized campaign.

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?

Two short sentences, zero filler. The payload description comes first and the access requirement is appended as a compact constraint, which is the right ordering for an agent scanning definitions.

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?

An output schema exists, so return values need not be explained, and both required parameters are fully described in the schema. The auth scope is stated, leaving only minor gaps such as behavior when the campaign does not exist or is outside the workspace.

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%, with campaign_id explicitly sourced 'from postly_list_campaigns' and workspace_id documented, so the schema carries the parameter burden. The description adds nothing about parameters beyond what is already structured, which is the expected baseline.

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 ('Fetches one Postly campaign') and enumerates the fields returned (brief, objective, audience, schedule, status, targets). The singular 'one' implicitly separates it from postly_list_campaigns, but it never names that sibling or postly_get_campaign_report, which is the nearest ambiguous neighbor.

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?

The only guidance is the permission requirement 'Requires campaigns.read.' There is no statement of when to reach for this tool versus postly_list_campaigns or postly_get_campaign_report, and no precondition such as needing a campaign_id obtained elsewhere.

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