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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so safety is covered. The description adds that specific fields are returned (helpful since there is no output schema) and the underlying endpoint, but says nothing about not-found behavior, permissions, or whether ext: lookups differ.

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 tight fragments with the purpose and id forms front-loaded ahead of the field list. The trailing 'GET /contacts/{contactId}' is marginally redundant for an agent but harmless.

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 one-parameter read tool with full annotation coverage, the description supplies the returned field set that the missing output schema would otherwise carry. Remaining gaps (not-found behavior, ext: lookup nuances) are minor.

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% and the schema description already fully explains both accepted id forms including the `ext:<customId>` convention. The description restates the same id semantics without adding format, validation, or lookup-behavior detail, so the baseline of 3 applies.

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: retrieves a single contact, and enumerates the returned fields (name, gender, email, company, fields), which separates it from evenium_list_contacts by singularity. It doesn't explicitly name the sibling it contrasts with (e.g. evenium_get_guest), so it stops short of a 5.

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 singular phrasing implies 'use this to fetch one known contact', but there is no explicit when-to-use or when-not guidance. Given the crowded sibling set (get_guest, list_contacts, get_contact_events), the description offers no rule for choosing between contact and guest lookups.

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