contact_getProfilePicUrl

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

The privacy caveat ('if privacy settings allow it') adds useful behavioral context, hinting that the result may be absent or restricted. However, with no annotations, the description still omits details about return format, failure modes, and whether any permissions are needed, leaving a moderate transparency gap.

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 short but repetitive: 'Get the profile picture URL' and 'Get the contact's profile picture URL' convey nearly the same information across two sentences. It could be condensed into one sentence without losing meaning, so it is not optimally concise.

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 a simple getter with no output schema, and the description covers its basic purpose and a key caveat. However, it does not address the optionality of contactId (only sessionId is required), nor does it hint at the return value structure. A more complete description would mention how the contact is selected when contactId is omitted.

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 fully documents both parameters. The description adds no additional parameter semantics beyond implying that 'the contact' refers to contactId. Baseline score of 3 is appropriate.

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 ('Get') and resource ('contact's profile picture URL'), making the core purpose clear. It does not explicitly contrast with sibling tools like client_getProfilePicUrl, but the 'contact' prefix in both name and description sufficiently distinguishes it.

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 guidance is provided on when to use this tool versus alternatives. The phrase 'if privacy settings allow it' describes a conditional outcome, not a usage context. Lacks any mention of when to prefer this over client_getProfilePicUrl or other contact-related tools.

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