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

readOnlyHint=true already tells the agent this is a safe read. The description adds value by disclosing the shape of the payload (name, email, phone, custom field data) and that notes are included only on request. It says nothing about error behavior for a nonexistent id, rate limits, or authentication, which is the remaining gap.

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?

One sentence plus an endpoint reference; the returned-field list and the optional-notes flag are front-loaded with no filler. Nothing is redundant.

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?

With no output schema, the description usefully describes the return payload, and annotations cover the safety profile, so the essential information is present for a simple two-parameter getter. Only not-found/error semantics are left unaddressed.

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 100%, so both parameters are already documented in the schema, and the baseline is 3. The phrase 'optionally with notes' loosely mirrors include_notes but adds no format, default, or cost detail beyond the schema.

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 specific verb and resource ('Fetch one contact') and enumerates the returned fields, so the agent knows exactly what the tool does. It implicitly separates itself from trengo_list_contacts by saying 'one contact', but never names a sibling tool 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?

There is no when-to-use guidance, no prerequisites, and no mention of alternatives such as trengo_list_contacts for bulk retrieval or trengo_get_ticket_details_report for related lookups. Usage is only implied by the tool name and purpose.

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