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

With no annotations at all, the description carries the burden and does well: 'Nothing is sent' establishes side-effect-free behavior, and it discloses the concrete cost (5 credits) plus a balance precondition. It omits what happens if the balance is insufficient (error vs. flag in the response), which is the one behavior an agent would still want.

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?

Three short clauses in a single sentence set, front-loaded with the dry-run nature and the cost. Zero filler; every phrase conveys a distinct fact (what, cost, no side effect, sequencing).

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?

No output schema exists, and the description compensates by describing the preview payload (recipient, text, cost, sufficiency). No annotations exist either, and it covers the no-op safety profile. The remaining gap is the chat_id identifier semantics, which is the only thing an agent could get wrong at call time.

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 0%, so the description must compensate. It loosely maps the two params — 'recipient' for chat_id and 'exact text' for text — but never clarifies what a chat_id actually is (a LinkedIn conversation ID? a contact ID?) or whether text is sent verbatim including newlines and length limits.

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?

States a specific verb+resource ('Dry-run' of a 'LinkedIn message') and enumerates exactly what the preview returns: recipient, exact text, credit cost, and balance sufficiency. It is unambiguously distinguishable from the sibling send_linkedin_message, which it names.

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?

'Call before send_linkedin_message and show the text to the user' gives explicit sequencing and the alternative to use afterward. It does not spell out when a preview should be skipped (e.g. re-previews of unchanged text), so it stops short of full when/when-not coverage.

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