linkedin_send_message

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

Beyond annotations (readOnlyHint=false), the description discloses that messaging outside the network requires InMail and that the tool will explicitly indicate when that is the blocker. It also mentions the max character limit. This adds useful behavioral context without contradicting any 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?

The description is three concise sentences, front-loaded with the main action, and each sentence adds value: purpose, InMail context, and character limit. No fluff or redundancy.

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 description covers key behavioral aspects (conversation initiation/continuation, InMail blocker, max length) and is reasonably complete for a messaging tool. It lacks details on return values or error handling beyond the InMail note, but the schema and annotations cover safety, so this is sufficient.

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 coverage is 100% and each parameter is already described in the schema (text, subject, identifier). The description only repeats the max length and adds no new semantic detail beyond the schema, 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 clearly states the tool sends a direct message to a person, with a specific verb and resource, and distinguishes itself from siblings like linkedin_reply_to_conversation by covering both new and existing conversations. The InMail note adds further specificity.

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?

It gives clear context for use: starting or continuing a conversation, and mentions the InMail requirement for out-of-network recipients. It does not explicitly name alternatives or say when not to use it, but the context is strong enough for an agent to choose appropriately.

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