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

Annotations already establish read-only, idempotent, non-destructive, closed-world behavior, so the description does not need to repeat safety traits. It adds useful behavioral context by listing exactly what contact data is returned and explaining came_from attribution, though it omits any permission or error behavior notes.

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?

The description is front-loaded and avoids redundant sentences, covering return contents, lookup method, attribution, and an alternative tool efficiently. However, the long run-on sentence and the vague 'when the site is counted' / 'Free' phrases reduce clarity slightly.

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 no-output-schema retrieval tool, the description does a reasonable job describing returned fields and the crm_timeline alternative. The main completeness gap is parameter behavior: with no required parameters and no schema descriptions, the agent still lacks clear guidance on identifier requirements or conflict handling.

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 0%, so the description must compensate for the two undocumented parameters. It says lookup is 'by id or email', which helps, but it does not state that at least one identifier is required, whether both may be supplied, which takes precedence, or the expected email format.

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 contact') and enumerates the returned data: tags, custom fields, activity, tasks, deals, and came_from attribution. It also distinguishes the tool from crm_timeline, which is described as the place for full history.

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 makes the usage context clear: retrieve a single contact by id or email. It explicitly points to crm_timeline for everything that happened with the contact, but does not distinguish from other retrieval/search siblings such as crm_find_contacts or crm_get_customer.

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