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

The readOnlyHint=true annotation already establishes this is a safe read, lowering the burden on the description. The description adds what fields come back, but says nothing about behavior on a missing/invalid id, permissions, or rate limits.

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 sentences, front-loaded with the core action, no filler. The field enumeration is long but earns its place since there is no output schema; slightly dense for a one-parameter lookup.

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?

Because no output schema exists, enumerating the returned fields is genuinely useful compensation, and the description even surfaces the brand_id path parameter that is absent from the input schema. Minor gaps remain around not-found/error behavior.

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?

With only one parameter and 100% schema description coverage, the schema fully documents contact_id, so the baseline is 3. The description's 'by id' is consistent with the schema but adds no syntax or constraint detail beyond it.

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 ('Get one contact by id') and enumerates the returned fields, so an agent knows exactly what it retrieves. It does not explicitly distinguish itself from the sibling slicktext_find_contact, which is the nearest alternative, so it falls 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?

'by id' implies the entry condition (you must already have a contact id), which is implied usage guidance. However, it never states when to prefer this over slicktext_find_contact or slicktext_list_contacts, and gives no exclusions or prerequisites.

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