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

Annotations only declare read-only/non-destructive, so the description carries the real weight: it explains the survival-bar screening, link-health probes, the 5-signal viability model, that the response declares which retrieval methods ran, and that unmeasured tools are listed separately rather than dropped. That last point is a genuine behavioral guarantee an agent could not infer from the schema.

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-loaded with the trigger and dense with actionable content — no sentence is filler. It runs long as a single block and carries some self-promotional phrasing ('unique to this catalog'), which keeps it just short of a 5.

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 six-parameter tool with no output schema, the description still tells the agent what comes back (health verdict, record rebuild date, pricing model, methods run) and how edge cases are surfaced. Nothing needed to invoke it correctly 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 the baseline is 3, and the description earns above it by adding a rationale the schema lacks: prices are verbatim in mixed currencies and never converted or compared, which explains why no price-amount parameter exists. It also frames survival_bar as a caller-set constraint, though the enum semantics themselves live in the schema.

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 (recommend/find) and resource (AI tool matched to a described need), with concrete example utterances that pin down the input shape. It also explicitly separates itself from check_tool_status and compare_tools, so an agent can route without opening either schema.

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?

Opens with an explicit trigger ('when the user describes what they need an AI tool to DO rather than naming one') and adds a 'Not for:' clause naming two siblings plus the exact exclusion case (price-amount filtering). Both when-to-use and when-not-to-use are stated with the alternative to pick instead.

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