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

With no annotations, the description must carry the behavioral burden. The word 'Find' and the optional parameters imply a safe read, and the default operator scope is disclosed, but the description says nothing about result ordering, pagination, or how name and proximity matches are combined when both are supplied. It is adequate but thin for a tool with zero annotation coverage.

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?

One front-loaded sentence gives purpose and mode selection, followed by a compact args list. The examples are genuinely useful, though the entry formats the operator descriptions across several lines and would benefit from tighter summarization.

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?

Since an output schema exists, return values do not need to be explained. The description provides the essential calling information, covering all parameters except limit, against a context of five params, no required fields, and no annotations.

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 0%, so the description has to carry the parameter load, and it defines query with four concrete examples, operator with concrete ids and a default, and lat/lon with the near-versus-name semantics. The limit parameter is left completely undocumented, which is the remaining gap.

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 opening sentence gives a specific verb ('Find') and a precise resource set (train stations, metro stations, bus/tram stops), and it distinguishes the two lookup modes: by name versus nearest to a point. An agent can immediately tell this is the transit stop lookup tool rather than the bus-specific sibling.

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 clearly states complementary usage: lat/lon 'find the nearest instead of (or as well as) by name', and it explains what the operator parameter accepts, including the default ('CP and the Lisbon operators') and the 'intercity' option. The only gap is that it never conditions when to prefer transit_find_stops over bus_find_stops.

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