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

The description adds substantial behavior beyond the annotations: it runs in the background, writes results to each person's record so list_sent_messages reflects names and companies, can take many minutes, costs 0.1 credits per profile plus 0.05 per new employer, is idempotent for already-looked-up/in-progress people, and raises when balance is insufficient. These are exactly the operational traits an agent needs.

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 summary is dense but front-loads the core purpose, then layers behavior, cost, idempotency, and error conditions in a logical order. The separate returns block is efficient and every sentence carries actionable information.

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?

For an asynchronous, credit-consuming, non-destructive mutation tool, the description covers what it does, how it runs, what it costs, what it returns, idempotency, and failure modes. Together with the structured return description, nothing material is missing for correct 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 100%, and both senders (shared-workspace filtering) and on_behalf_of (agency client context) are fully documented in the schema. The description adds no parameter-level detail, so the baseline 3 applies.

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 states a specific verb and resource with precise scope: looking up LinkedIn profiles of people the user has imported conversations with whose profile hasn't been looked up yet. This is clearly distinguishable from siblings like enrich_linkedin_profiles or import_linkedin_history, and the 'Messages tab's Look up' reference anchors it.

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 usage context: background execution, tell the user it's running rather than waiting, and that already-looked-up or in-progress people are skipped. It doesn't explicitly name an alternative tool (e.g., enrich_linkedin_profiles) or state when not to use this one, so it falls short of a 5.

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