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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds connected-account scope and trigger semantics, but doesn't disclose additional behavior such as error conditions, stale data, or whether a connection must first exist. No contradiction with annotations.

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?

Two compact sentences with no filler. The core action is front-loaded and the usage trigger is given immediately, making it easy for an agent to scan and apply.

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?

A read-only tool with one optional parameter is fully covered by the description plus the rich account_id schema. There is no output schema, but 'credit information' and 'how many credits remain' give enough semantic context for an agent to know what the tool returns.

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% and the account_id parameter already includes detailed guidance about omitting it, listing accounts, and disambiguation. The description does not need to repeat parameter details, so the baseline 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 names a specific action ('Get'), resource ('LinkedIn InMail credit information'), and scope ('for the connected account'). The second sentence adds the user-facing trigger, making it easy to distinguish from sending or invitation tools like linkedin_send_message.

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?

'Use when the user asks whether an InMail can be sent or how many credits remain' is explicit and actionable context. It doesn't name an alternative tool or state exclusions, but the use case is sufficiently distinct from siblings.

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