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

The annotations already declare readOnlyHint=true, so the agent knows this is a safe read operation. The description adds the underlying REST method (GET /contacts/{id}), which is useful but does not go beyond that. No additional behavioral traits (e.g., response format, error conditions, rate limits) are disclosed, so the added value over annotations is minimal.

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?

The description is extremely concise: two short sentences with no redundant information. It front-loads the core purpose ('Get a single contact by id') and follows with the REST endpoint for clarity. Every word 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?

The tool is simple with one parameter (id) and no output schema or enums. The description, combined with the readOnlyHint annotation and schema coverage, provides enough context for an agent to use it correctly. It does not explain the response structure, but this is a straightforward lookup operation where the return value is implicit. The main gap is the lack of any error/edge case mentions, but these are not critical for a simple get-by-id.

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?

The schema description coverage is 100%, with the 'id' parameter fully described as 'The contact id.' The description reinforces that the id is used to fetch a single contact. Since the schema already provides complete parameter meaning, the description adds no extra semantic value beyond confirming the purpose.

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 the specific action: 'Get a single contact by id.' This distinguishes it from sibling tools like freshdesk_list_contacts (list all), freshdesk_search_contacts (search), freshdesk_create_contact, and freshdesk_update_contact. The inclusion of the REST endpoint further clarifies the exact operation.

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 context is clear: you use this tool when you have a contact id and need the corresponding contact record. The description does not explicitly list alternatives or exclusion criteria, but the resource-specific framing ('contact by id') makes the intended use unambiguous given the sibling set.

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