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

Goes well beyond the annotations: 'It sends nothing and makes no account changes,' 'Eligibility and offer amounts are unknown until the vendor confirms them,' plus explicit data-handling disclosure about what Stackcut stores (vendor/price/seat/feature/usage data, account keys hashed, billing and validation sources not stored, never IPs) and how results are summarized. This is unusually rich behavioral context for a read-only tool.

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?

Front-loads purpose and return contents before safety and privacy, so the important material is early. It is dense and the privacy/storage sentence is long, but for a 13-parameter tool with no output schema most of it 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?

With no output schema, the description correctly enumerates what comes back ('channel- and market-specific paths, vendor sources, freshness, questions and draft request/terms/counteroffer/decline/confirmation scripts') and covers safety, data handling and comparison semantics. The main omission is any guidance on picking this tool over overlapping siblings.

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 only 23%, so the description must compensate and it partially does: it maps conceptually to offered/renewal prices, offer duration, fees, comparison horizon, and the currency/billing-cadence constraint tied to monthly_spend. It adds nothing for service, market, billed_by, current_plan, renewal_date, required_features or maximum_commitment_months, leaving a real gap across ~13 params.

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 and resource: 'Find documented existing-customer offers, cancellation-flow promotions and renewal negotiation routes for a service.' This clearly separates it from generic exit/alternatives tools, but it never names a sibling such as search_exits or get_exit_plan, so the agent must infer the boundary itself.

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?

There is no when-to-use guidance and no named alternative. The line 'Compare costs only with complete prices... explicit horizon' is a precondition for good input rather than routing guidance, and nothing tells the agent when NOT to call this versus its many siblings.

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