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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, and the description reinforces rather than contradicts them while adding the genuinely non-obvious note that the call 'does not advance the unread cursor'. It also exposes the underlying REST route (GET /v1/campaigns/{id}) and the returned field set, which matters since no output schema exists. Minor gap: no mention of error behavior for an unknown id.

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?

Front-loaded with the core action and returned fields, then routing, then behavioral notes; the fragmentary style packs a lot into three sentences. 'Idempotent' and the REST route are somewhat redundant with the annotations and title, but they cost little.

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 one-parameter read tool with rich annotations and no output schema, the description supplies everything an agent needs: what it returns, what it does not do (cursor), where to go for mutations, and how to obtain the id. Nothing material is missing.

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?

With a single parameter and 100% schema description coverage, the schema already carries the semantics, including that omitting the id falls back to the Space's default Campaign and that ids come from list_campaigns. The description only repeats the parameter name, adding no format or resolution detail beyond the schema, 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?

States a specific verb and resource ('Get one Campaign by campaign_id') and enumerates the fields returned (id, name, owner, status). It explicitly distinguishes itself from the sibling 'campaign' tool's action get and from the mutation actions, so an agent can tell it apart without opening either schema.

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?

'Prefer this over campaign action get' names the alternative and the preference; 'Open, park, resume, close, and reassign_owner stay on campaign' explicitly routes all mutating operations away from this tool. The schema additionally points to list_campaigns for id discovery, covering the read path end to end.

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