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

No annotations are provided, so the description carries the behavioral burden. 'Look up' implies a read-only operation and the return list gives useful context, but it does not disclose behavior when neither parameter is provided, when both are provided, or when no matching agent is found. For such a simple read tool this is adequate but not complete.

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, front-loads the verb and resource, then lists the return fields. Every word earns its place, and the core semantics are immediately available.

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 two optional parameters and no output schema, so the description covers the main purpose and return fields. However, the mismatch between the schema (required: []) and the description ('by name or ID') leaves ambiguity about whether at least one parameter is needed, and there is no mention of failure behavior. This is a noticeable gap for correct invocation.

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 the schema already documents each parameter. The description adds the relationship ('by name or ID') that they are alternatives, which is helpful, but it doesn't specify what happens if both are supplied or if none are supplied. This is baseline value for full schema coverage.

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 states a specific verb ('look up'), a specific resource ('an agent'), and the lookup keys ('by name or ID'). It also lists the returned fields, making the tool's purpose unmistakable and distinct from siblings like get_asset or register_agent.

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?

The description clearly implies when to use this tool: whenever an agent's details are needed. It does not explicitly exclude alternatives, but among the siblings none competes for the same agent-lookup purpose, so the context is unambiguous. It lacks an explicit 'use this for...' statement but is otherwise clear.

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