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

Annotations already declare this a safe, idempotent, read-only, open-world operation, so the bar is lower. The description adds real behavioral context beyond them: matching semantics (all space-separated terms must match, i.e. AND) and the Traditional Chinese input requirement. It does not disclose result ordering, result-count behavior, or how limit truncates matches.

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 sentences, zero waste. The scope and language constraint come first, and the matching rule plus example follow immediately, making the most failure-prone aspect (query formatting) front-loaded.

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?

An output schema exists, so return values need not be explained. For a text-search tool the description covers the language, the match semantics, and the scope; the only gap is what limit does to the result set, which is minor given the schema's explicit max of 20.

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 33% (city documented via enum/description; query and limit undocumented). The description compensates for the most important gap by explaining query's tokenization and AND-matching rules and giving a concrete Chinese example, which the schema does not state. Only limit remains unexplained anywhere.

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 (Search) and resource (one city's stops) plus the scoping dimension (district/village/location/route text). It implicitly separates itself from find_nearby_points by being text-based rather than proximity-based, though it never names the sibling outright.

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?

Usage is only implied: the phrase 'Search one city's stops by ... text' suggests this is for textual lookup versus find_nearby_points' geographic lookup, but there is no explicit when-to-use statement, no exclusion, and no mention of list_cities as a prerequisite for valid city ids.

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