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

With no annotations provided, the description carries the full burden of behavioral disclosure. It implies a read-only lookup operation, but does not detail whether it searches the local address book, Exchange, or other sources, nor does it mention case sensitivity, partial matching, permissions, or error behavior. The description is minimal and leaves these aspects opaque.

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 a single, concise sentence that immediately communicates the tool's function without any filler or repetition. It efficiently uses the limited space to convey the essential purpose and parameter semantics.

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?

For a simple lookup tool with one parameter and no output schema, the description is largely sufficient. It clarifies the resource and the search criterion. While it lacks details about return values or limitations, the simplicity of the tool and the absence of an output schema mean the description does not need to over-explain. It is complete enough for an agent to understand the core intent.

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 input schema has one parameter 'q' with no description (0% schema coverage). The description adds meaning by stating the lookup is 'by name', directly indicating that 'q' represents the contact name. However, it does not clarify formatting, formatting requirements, or whether partial names are supported, leaving some ambiguity.

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 'Look up a Microsoft contact by name' clearly identifies the specific action (look up), resource (Microsoft contact), and the lookup criterion (by name). This distinguishes it from sibling tools like create_outlook_contact or lookup_contact, which may have broader or different purposes.

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 provides no explicit guidance on when to use this tool versus alternatives, such as search_outlook or get_outlook_inbox. It does not mention prerequisites, exclusions, or conditions that would direct an agent to this tool over similar ones. The usage context is only implied by the tool's name and description.

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