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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds the constraint that the ID must come from search_contacts or list_contacts, which is useful. However, it does not disclose behavior for invalid or missing IDs, rate limits, or any other operational details. With annotations present, this is acceptable but not 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?

A single, efficient sentence with zero wasted words. It front-loads the action and resource, then immediately clarifies the ID source. Perfectly concise for a simple get-by-ID tool.

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?

The description is sufficient for an agent to call the tool correctly: it states the purpose and the exact provenance of the required parameter. With an output schema present (though not shown) and annotations covering safety, the description covers what is needed. Minor gaps like error handling might be handled by the output schema, so this is complete enough.

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?

The schema has no description for contactId (0% coverage), so the description carries the burden. It clearly explains that the parameter is an ID returned by specific tools, giving the agent meaningful guidance on what to pass. This compensates well for the schema gap, though it could specify expected format or type beyond string.

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 ('Get'), a specific resource ('one contact'), and the exact identifying source ('by an ID returned by search_contacts or list_contacts'). This clearly distinguishes it from other getters like get_case or list_contacts, and it is not a tautology.

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 description implies the tool is used when you already have an ID from search_contacts or list_contacts, which provides clear context. However, it does not explicitly state when NOT to use it (e.g., when you need to search by criteria) or name alternatives beyond the implied source. It is contextual but lacks explicit exclusions.

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