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

With only `destructiveHint: false` provided, the description carries most of the burden and does so well: it discloses the access restriction (internal staff only), that the operation is a record of a past event rather than an action, and the downstream effects (populates the `outreach` field in `get-signup-funnel` and shows as 'contacted' on the admin trials page). It doesn't cover idempotency or what happens on duplicate entry.

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 staff-only restriction and the core action are front-loaded, and the paragraph break separates purpose from usage rules. A few sentences are slightly redundant ('Only call this when you have been told it went out' overlaps with 'Sending is not something this tool does'), but nothing is padding.

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 a 6-parameter mutation with no output schema and minimal annotations, the description supplies access restrictions, the when-to-record rule, the downstream visibility, and the ID source. An agent has enough to call it correctly; only duplicate-handling behavior is unaddressed.

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%, so a baseline of 3 applies, but the description adds real meaning: it tells the agent where to source `team_id`, and explains why `sent_at` matters ('so the row shows how long the silence has really been'), which is motivation the schema lacks. The remaining parameters are left entirely to their schema text.

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 uses a specific verb ('Record') on a well-defined resource ('a person reached out by hand to a signed-up account (a trial or customer team)'), and it explicitly clarifies that sending is out of scope. The parenthetical defining the target as a trial/customer team implicitly separates it from the prospect-side siblings, but it never names `record-prospect-outreach-tool`, so the differentiation is inferred rather than stated.

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?

'Only call this when you have been told it went out' is an explicit call condition, and 'Sending is not something this tool does' is an explicit exclusion. It also routes the agent to `get-signup-funnel` for the team `id`, and instructs passing `sent_at` for backdated records. It stops short of naming the closest alternative tool for prospect outreach.

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