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

Goes well beyond annotations: specifies 8-credit cost charged only on return, free repeat batch for a week, free skip-only calls, permanent dedupe via record_action, a model-call filter excluding vendors/marketers/bots, and a strict never-guess-email policy. That is exactly the mutation/cost/irreversibility context 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?

A dense run-on with an awkward fragment ('Costs 8 credits, charged only when it returns. for a new batch, charged only when it finds someone new') and repetition about charging. The core scope is front-loaded, but the sentence structure makes the cost rules hard to parse.

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, yet the description enumerates the return payload per person (post and words, why it shows pain, opening angle, verified email or a note plus the thread). Combined with the cost and dedupe rules, an agent knows what it will get and what it costs; only cross-sibling routing is missing.

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 baseline is 3, but the description adds real param meaning: `skip` calls are free and permanent, `fresh` overrides last week's batch, and repeat batches are charged only when new people are found. Adds value over the schema's own descriptions.

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 outcome: people who publicly said in the last two weeks they have the problem the product solves, on X and Hacker News, never Reddit. That scope and the Reddit exclusion clearly separates it from targets-style siblings. The verb is implied ('people who...') rather than named, keeping it just short of a 5.

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?

Describes when to use `fresh` (find a new batch) and `skip` (record skips free), and that written-to/skipped people never return. But it never names or contrasts the obvious siblings (outreach_targets, launch_targets, reach_find, boost_candidates), so selection among similar tools is left to inference.

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