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

readOnlyHint=true already covers the safety profile, so the bar is lower; the description still adds value by disclosing the returned content (message, recipients, status). It does not mention auth requirements, pagination, or error behavior for a missing id, keeping it short of 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?

Two short sentences, front-loaded with purpose and return content, followed by the REST endpoint. No sentence is redundant or padded.

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?

Annotations cover the read-only safety profile and there is no output schema, so the description correctly supplies the return fields and lookup key. It is essentially complete for a single-parameter read tool, though it omits any note on failure behavior for an invalid id.

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 description coverage is 100% and there is only one parameter, already documented as 'Campaign id.' The description restates 'by its id' but adds no format or sourcing 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 (get), resource (campaign), and scope (a single campaign by id), and enumerates what it returns (message, recipients, status). The word 'single' plus the id-based lookup cleanly distinguishes it from simpletexting_list_campaigns.

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 id-based lookup implies this is for retrieving one known campaign, which contrasts implicitly with the list sibling. However, it never explicitly names an alternative or states when-not to use it, so usage is inferred rather than spelled out.

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