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

Annotations already mark readOnlyHint=true and destructiveHint=false, and the description adds valuable behavioral context: it aggregates stated and learned preferences and frames itself as 'the single best source of who this traveler is.' It does not contradict the annotations.

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 description is three sentences with no filler: definition, usage instruction, and alternative tool routing. It is front-loaded with the core purpose and every sentence 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?

For a zero-parameter read-only tool with an output schema and annotations, the description fully covers what data the tool returns, when to call it, how to use its output, and how it relates to a key sibling tool. Nothing essential 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?

The tool has 0 parameters, so schema description coverage is effectively complete. No parameter explanation is needed, and the description does not introduce any misleading parameter-related information.

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 clearly states what the tool does: 'Get the user's saved travel context' and enumerates the contents (loyalty programs, home airport, preferred airlines, hotel chains, trip patterns). It also distinguishes itself from get_past_trips by noting the latter provides raw past reservation evidence, so an agent can tell them apart.

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?

The description gives explicit usage direction: call it once at the start of a travel or planning session and weigh it when recommending hotels, flights, or cars. It also names a specific alternative (get_past_trips) for raw past-reservation evidence, providing clear when-not-to-use guidance.

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