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

Annotations already declare readOnlyHint and openWorldHint, and the description adds real context: results come from Viator, ranking prioritizes trip intent over the city's default best, and a fallback is mentioned 'when the row is thin.' The fallback phrase is too vague to be actionable, but the sourcing and ranking behavior are genuine additions beyond 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?

Two compact sentences with the resource and provenance front-loaded. Some phrasing is convoluted ('what the trip is for first, the city's best otherwise,' 'a second place to look when the row is thin'), which slightly blunts otherwise efficient text.

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 2-parameter read-only tool with annotations and no output schema, the description covers input provenance and ranking logic but says nothing about what the response contains or how many results come back. The vague 'second place to look' reference leaves an agent unsure what it is being pointed at.

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 only 50% and searchId has no description at all in the schema, so the description's guidance to source it from search_stays or city_picks compensates meaningfully. It also clarifies that intent overrides the search's own context, adding semantics beyond the schema's brief 'Override' note.

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 resource and source: 'Top-rated things to do on Viator for a search's spot and dates.' It is clearly a discovery/listing tool, distinguishable from get_stay and search_stays by naming the thing it returns, though it never uses a direct verb like 'get' or 'list'.

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?

'Pass a searchId from search_stays or city_picks' gives the explicit prerequisite and names the two sibling tools that produce the input. It states the intent-override rule but offers no when-not-to-use case or routing versus other content tools.

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