contacts_get_photo

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 clearly states that the tool returns a photo URL, but it does not mention edge cases such as missing photos, error conditions, or required permissions. This is minimally sufficient for a simple read operation but lacks depth.

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, front-loaded sentence with no filler or redundancy. It communicates the tool's core purpose efficiently and is appropriately sized for a simple getter tool.

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, has one parameter, and an output schema exists to document return values. However, the description lacks input semantics and usage guidance, so an agent may not know how to construct resource_name. It is adequate for basic selection but not fully complete for reliable 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?

The input schema has zero description coverage for resource_name, and the tool description only says 'for a contact,' implying the parameter identifies a contact but not how the string should be formatted or where it comes from. Since schema coverage is 0%, the description should compensate but does not provide enough parameter-level detail.

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 uses a specific verb ('Get') and resource ('photo URL for a contact'), making the tool's purpose immediately clear. It also distinguishes this tool from sibling contacts tools like contacts_search, contacts_list, and contacts_update, as it is the only one focused on photo retrieval.

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 implies this tool should be used when you need a contact's photo URL, but it provides no explicit guidance on when to use it versus alternatives or how to obtain the required resource_name (e.g., via contacts_search or contacts_list). The usage context is only implied, not fully explained.

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