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

readOnlyHint=true already tells the agent this is a safe read, so the description's burden is lighter, yet it still adds almost nothing: 'full' hints at a complete object versus a summary but never says what is returned, whether it is paginated, or whether it errors on unknown IDs. Beyond the annotation, there is no behavioral context.

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?

A single front-loaded sentence with zero filler, appropriately sized for what it attempts. Its brevity is not the problem — the omission of routing and return information is.

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 six-parameter tool with no output schema, the agent is told nothing about the shape of 'full campaign details' or what distinguishes it from lemlist_campaign and lemlist_get_campaign_stats. The read-only annotation covers safety, but selection among near-identical lemlist siblings remains unresolved.

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 83% and the plumbing parameters (_org, _project, _instance, _run_id, _group) are documented in-schema with operational instructions. campaign_id itself has no schema description, but the description's 'by ID' supplies its meaning, 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?

The description states a specific verb and resource ('Fetch full campaign details') scoped 'by ID', so the agent knows this is a single-object read rather than a list. It does not, however, distinguish itself from close siblings such as lemlist_campaign, lemlist_list_campaigns, or lemlist_get_campaign_stats, leaving the boundary to inference.

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?

There is no explicit when-to-use guidance and no named alternative. The phrase 'by ID' weakly implies the caller must already hold a campaign_id (obtainable via lemlist_list_campaigns), but that prerequisite is never stated.

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