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

Annotations already declare readOnlyHint/idempotentHint/destructiveHint=false, so the safety profile is covered. The description adds genuine behavioral context beyond that: results are pre-aggregated rollups (accounts by status, gaps, staleness) rather than raw rows, plus a domain warning (CRM-13) that every why_them argues against adding accounts without reading the goal. It does not describe cost, size, or pagination, so it adds value without being rich.

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 sentences, front-loaded with the payload inventory and zero filler. The trailing '— the per-goal Today' clause is compressed to the point of being unclear, which costs it a point, but nothing is wasted.

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 no parameters, no output schema, and safety already covered by annotations, the description gives enough to call the tool and to know what fields arrive. However, for a read-only survey tool in a crowded CRM namespace it should say how it relates to crm_today, crm_gaps, and crm_pipeline, which return overlapping information — that routing gap is the main missing piece.

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?

Zero parameters and an empty schema, so there is nothing for the description to disambiguate; the baseline applies. The description correctly implies no filtering is possible on this call, since all scoping happens at the aggregate level.

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 the resource (every campaign) and enumerates what comes back — goal, status, health, accounts by status, open gaps, staleness — which separates it from the singular crm_get_campaign. The opening is a noun phrase rather than a verb, and 'the per-goal Today' is opaque jargon, but an agent can still tell this is the campaign-level rollup view.

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 second sentence gives a workflow instruction ('read the goal before adding accounts to a campaign'), but that governs the downstream add-account action, not when to select this tool over siblings. It never names crm_get_campaign, crm_pipeline, crm_gaps, or crm_today, even though the returned fields ('open gaps', 'per-goal Today') overlap those tools directly.

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