client_getContactLidAndPhone

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

No annotations are provided, so the description carries the burden of disclosing safety. 'Retrieve' implies a read-only operation, which is useful, but the description does not explain edge cases (e.g., missing contact, invalid session) or what 'lid' means. It is adequate for a simple getter 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 short and front-loaded, but the second sentence largely repeats the first ('Get contact lid and phone' vs 'Retrieve the contact lid and phone number'). It is still efficient, with no unnecessary fluff.

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?

While the tool is simple (2 params, no output schema), the description is incomplete: it does not explain the relationship between 'specific chat' and userIds, lacks any output format detail, and leaves the term 'lid' undefined. These gaps could lead to incorrect 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 only 50%: the userIds property lacks a property-level description and the tool body does not clarify it. The description mentions 'specific chat' but the parameters are sessionId and userIds (user identifiers), not a chatId, creating ambiguity. The tool description adds no meaningful parameter semantics beyond the minimal schema.

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 clearly states the tool's function with a specific verb ('Get'/'Retrieve') and resource ('contact lid and phone'), and adds scope ('for a specific chat'). This distinguishes it from sibling tools like client_getContactById or client_getContacts, which are broader or return different fields.

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 phrase 'for a specific chat' implies a use case, but there is no explicit guidance on when to choose this tool over alternatives such as client_getContactById or client_getNumberId. No exclusions or alternative tool references are provided.

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