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

Annotations already declare the safe read-only, idempotent profile, but the description goes further: it lists the returned fields, warns that only 'a few live matches' come back, enforces one-place-per-call, and forbids fabricating handles. That is meaningful behavioral context, though it stops short of covering ambiguity handling or match-miss behavior when nothing resolves.

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 purpose, then trigger, then return fields, then routing rules – a sensible order with no filler sentences. It is slightly long, and the three-sibling routing block is dense, but every line carries actionable information.

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 resolver tool with a full output schema, annotations covering safety, and 100% param coverage, the description supplies exactly the missing pieces: when to call it, what it returns conceptually, and which sibling to call next. Nothing an agent needs to invoke it correctly is absent.

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 100%, so both parameters are already documented, making 3 the baseline. The description adds usable input examples for 'query' (paris, hanoi, IATA code) and the 'One place per call' constraint, but says nothing about page_size or how result counts behave.

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 ('Resolve') and resource ('a city, country, region, or airport onto Sorted destinations'), and clearly separates itself from the get_destination_info/weather/recommended siblings by naming each. An agent can distinguish it without opening any other 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?

Gives an explicit trigger ('when the traveler names a place and you do not already have a sitemap handle ... or IATA code') and conditionally routes to three named alternatives with the conditions that select each. It even adds a negative constraint ('Do not invent a handle') and a cardinality rule ('One place per call').

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