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

readOnlyHint=true already tells the agent this is a safe read, so the bar is lower, but the description adds almost nothing beyond the raw endpoint path. It says nothing about behavior for 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 short fragments with the resource and scope front-loaded; nothing is padded. It is borderline terse rather than wasteful, and the raw HTTP path is the least useful sentence.

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?

There is no output schema, so the description is the only place the return shape could be described, and it says nothing about what a contact record contains or how errors surface. For an otherwise simple one-param read this leaves a real gap.

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%, and the schema already documents contact_id as coming from the list tool plus its integer/string format. The description adds no parameter meaning beyond that, so the baseline 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 the resource (business contact) and a single-record scope ('by id'), which distinguishes it from ezrentout_list_business_contacts. The verb is only implied ('One business contact by id') rather than stated, and no sibling is named in the description itself.

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?

No explicit when-to-use guidance or exclusions. The agent must infer from 'by id' that this is the single-record counterpart of the list tool, and the schema's parameter note ('from ezrentout_list_business_contacts') is the only routing hint.

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