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

Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=true), so the description's job is to add context — which it does by disclosing the exact payload an agent will receive, valuable since there is no output schema. It omits error behavior for unknown contacts and any auth/rate-limit notes, keeping it short of 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 tight sentences with the payload description front-loaded and the endpoint form last. The 'GET /contacts/{contact_id}?list_id=...' fragment is mildly redundant with the schema, but it reinforces the id-scoping relationship cheaply.

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 two-parameter read with no output schema, the field enumeration is exactly the missing piece an agent needs to decide whether to call this versus a list tool. Only the not-found / cross-list-mismatch behavior is unaddressed, which is a minor gap for a simple getter.

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 both parameters are already documented, but the description adds the non-obvious semantic that a contact is list-scoped — contact_id alone is insufficient and list_id constrains which record is returned. That is a real clarification beyond 'Numeric id (as returned by the list tools)'.

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 clearly states it returns a single contact scoped to a single list and enumerates the fields returned (status, email, name, IP, source, timestamp, custom fields). It implicitly separates itself from emailchef_list_contacts by emphasizing 'one contact in one list', but it never names that sibling explicitly.

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 only implied: the 'one contact in one list' phrasing tells an agent this is the single-record lookup requiring both a list and a contact id. There is no explicit when-to-use statement, no mention of emailchef_list_contacts for browsing, and no note about what happens when the contact isn't in that list.

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