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 still adds real context: default sort order, the fields returned, and the required scope "campaigns.read," which an agent needs before calling.

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?

Three short sentences, front-loaded with the core operation, then filters, then return shape and permission. Nothing is redundant with structured fields in a wasteful way and every sentence 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?

For a simple read/list tool with full schema coverage, an output schema and rich annotations, the description covers ordering, filtering, returns and authorization. The one omission is pagination direction (that 'before' walks backward through older campaigns), which the schema hints at but the description leaves implicit.

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% — limit, before, search, status and workspace_id are all documented in the schema, including the enum and the cursor semantics. The description restates the filter axes (status, name prefix, CAM- ID) without adding syntax or interaction rules such as whether search and status combine, so the baseline of 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?

The description uses a specific verb and resource ("Lists Postly campaigns in a workspace") and adds default ordering ("newest first") plus supported filter axes, which lets an agent distinguish it from single-object siblings like postly_get_campaign. It never names a sibling explicitly, so the boundary with postly_list_ad_campaigns or postly_list_campaign_posts must be inferred.

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?

Usage is implied by the filter list — an agent can tell this is the browse/enumerate tool — but there is no explicit statement of when to prefer it over postly_get_campaign or postly_list_ad_campaigns, and no exclusions or prerequisites beyond the permission note.

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