Send Message

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

Annotations already indicate destructiveHint and openWorldHint. The description adds valuable specificity by clarifying that the write operation only executes when confirm_send is True, and it highlights a real-world constraint (recipient must be directly messageable). This goes beyond the raw annotation hints.

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 clear sentences with no fluff. The first sentence states the action, the second gives the critical prerequisite and write condition. Every word earns its place.

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?

Given the tool's complexity (4 params, all documented) and the presence of an output schema, the description adequately covers the core behavior. It leaves typical implementation details to the output schema. A bit more about potential side effects or post-send behavior would make it perfect, but it 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 description coverage is 100%, so baseline is 3. The description itself does not add parameter-level semantics, but the schema already fully documents each parameter, including the profile_urn bypass behavior and the confirm_send requirement. No further explanation is needed.

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 'Send a message to a LinkedIn user' with a specific verb and resource. This unambiguously identifies the tool's purpose and naturally distinguishes it from sibling tools like connect_with_person (connection requests) and get_inbox (reading messages).

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 gives a prerequisite ('The recipient must be directly messageable from the profile page') and notes the write condition (confirm_send=True), but it does not explicitly contrast with alternatives or state when not to use it. The usage context is implied rather than fully spelled out.

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