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

Annotations already declare readOnlyHint=false, destructiveHint=false, idempotentHint=false. The description adds genuinely useful context beyond that: 'Nothing is sent to the contact', which reassures the agent no email/SMS side effect occurs, plus the POST endpoint. It does not mention the duplicate-creation risk implied by idempotentHint=false, so not 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 terse sentences, front-loaded with the 'WRITE:' classification, and zero 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 9-parameter create tool with no output schema, the description covers the required field, optional related data, and side-effect context. It stops short of indicating what is returned (e.g. the new person's id), which the agent would need for follow-up calls, so it is good but not fully complete.

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 78% and the schema documents every parameter including nested email/phone structure, limits, and the quirky country_code-as-language field. The description only restates the last-name requirement and optional emails/phones, adding little beyond the schema. Baseline 3 is appropriate.

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 ('create') and resource ('contact person'), calls out the required field (last name), and names the optional related data. It is clearly distinguishable from the sibling create_company/create_deal/create_task tools.

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?

Usage is implied by 'create a contact person', but there is no explicit statement of when to use this versus update_person (for existing contacts) or the create_* siblings. An agent must infer the choice from the verb alone.

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