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

Annotations only provide destructiveHint=true and a title; the description adds meaningful context beyond that by disclosing required field ('name is required') and the mapping behavior for email/phone (convenience strings mapped to structured arrays). It does not mention permissions, duplicate handling, or return format, but the mapping disclosure is substantive extra value.

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 compact sentences: purpose first, then required-field and mapping details, then the REST endpoint. No filler; every clause earns its place.

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 6-param create tool with no output schema, the description covers the required field, the non-obvious mapping behavior, and the endpoint. It omits duplicate-handling guidance and what the response returns, but is largely complete for correct invocation.

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 coverage is 100%, so the schema already documents all six parameters. The description adds the useful mapping semantics for email/phone (convenience strings -> structured arrays), which is not obvious from the schema, but adds nothing for org_id/owner_id/visible_to. Baseline 3 with slight added value.

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+resource ('Create a new person (contact)') and disambiguates the resource with the parenthetical 'contact'. Clearly distinguishable from siblings like create_deal, create_activity, and add_note.

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?

Implies usage (creating a contact) but gives no when-to-use vs alternatives such as search_persons (to check for duplicates first) or get_person. No exclusions or prerequisites stated.

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