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

Annotations already establish that this is a non-read-only, non-destructive, closed-world write. The description adds nothing beyond that: no mention of deduplication against existing contacts, permission/ownership requirements, or what happens to the seven required identifiers.

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?

Three words is not conciseness but under-specification; it is front-loaded but has no substance to front-load. Nothing about the 12-parameter surface is conveyed.

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 tool with 12 parameters, 7 of them required, 2 enums, no parameter descriptions, and no output schema, a four-word description is wholly inadequate. An agent has no basis for constructing a valid call.

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% across 12 parameters, so the burden falls entirely on the description, which conveys zero parameter meaning. Critical details such as the 'source' default of 'manual' or the distinction between sourceUrl/sourceProvider/sourceReference are left completely undocumented.

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 gives a clear verb+resource ('Add a contact'), and 'by hand' hints at manual entry, which distinguishes it loosely from find_prospect_contact/select_prospect_contact. But it says nothing about what a 'contact' is scoped to here (project/site/prospect), so it does not cleanly separate itself from add_prospect or verify_contact.

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?

There is no guidance on when to use this versus find_prospect_contact, select_prospect_contact, add_prospect, or verify_contact, all of which live in the same contact/outreach area. No prerequisites or exclusions are stated.

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