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

Annotations already set readOnlyHint=true and destructiveHint=false. The description adds value by disclosing 'No points are consumed' (cost implication) and 'live capabilities' (freshness/dynamic data). No contradiction with annotations; the extra behavioral context beyond the structured hints is useful.

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?

Three sentences, each serving a distinct purpose: purpose, usage guidance, and cost note. No filler or redundancy. The description is front-loaded with the primary action and remains highly scannable.

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 simple read-only info tool with an output schema, the description fully covers purpose, when to use it, and cost behavior. It doesn't need to explain return format because the output schema exists. The guidance to call it first is a complete workflow hint.

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?

The tool has zero parameters, so the baseline is 4. The description compensates for the empty schema by listing what the tool returns (capabilities, prices, limits, endpoints, workflow), giving semantic meaning to the output.

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 starts with 'Read Xcatcher's live capabilities, prices, limits, endpoints, and recommended agent workflow' – a clear verb (Read) and specific resource list. It clearly differentiates from sibling tools (task/payment management) by focusing on service-level info.

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 explicitly advises 'Call this first when planning a crawl or when cached documentation may be stale,' providing both a condition and a recommended workflow. This tells the agent exactly when to invoke this tool relative to other actions.

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