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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world). The description adds meaningful context beyond that by enumerating what the response contains, including the dry-run vs live delivery mode and counters. It does not mention behavior for an invalid or missing campaign_id, which keeps it from a 5.

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?

One short sentence, front-loaded with the core resource ('One campaign'), with no redundant or filler text. Every clause (steps, status, delivery mode, counters) adds 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 single-parameter read tool with full annotations and no output schema, the description covers the essential return contents. Only minor gaps remain, such as error behavior for an unknown campaign_id or whether the returned steps are paginated.

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?

There is a single parameter with 100% schema coverage ('Campaign id.'). The description adds no syntax, format, or lookup semantics beyond what the schema already states, 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 states a specific verb and resource: fetch 'One campaign' and returns its steps, status, delivery mode and counters. The singular 'One campaign' implicitly distinguishes it from list_campaigns and the mutation siblings, but no sibling is named explicitly.

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 only implied: an agent infers it should call this when it has a campaign_id and needs details for a single campaign. There is no explicit when-to-use/when-not-to-use guidance or reference to alternatives like list_campaigns or campaign_report.

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