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

Adds substantial context beyond the annotations: data is provisional, open licence with warnings, no key needed, and concrete anonymous rate limits (60/hour, 300/day per IP and session) with key-based fallback. It does not describe result shape or what happens when a name matches multiple stations, but the operational constraints are well covered.

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 core purpose is front-loaded and the nrw_measures linkage is well placed, but 'TerraMCP is a Wrench AI service' is pure filler and the licence/auth/rate-limit sentences are dense boilerplate that could be trimmed without losing agent-relevant 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?

With only two params and no output schema, the definition covers licensing, rate limits, provenance, and SI normalisation of hydrological units. The one gap is that it never tells the agent what a returned 'station reference' looks like or how to handle zero/many matches.

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 100%, so both `name` and `limit` are already documented in the schema. The description restates name-based searching but adds no syntax hints (partial matching, case sensitivity) or guidance on choosing `limit`, so it sits at the baseline.

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 and resource ('Find Natural Resources Wales telemetry stations by station name') and links the output to the sibling consumer nrw_measures, which separates it from nrw_measures/nrw_readings. It does not explicitly distinguish itself from other provider station finders (sepa_stations, ea_groundwater_stations), but the provider scope is unambiguous.

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?

'Returns station references for nrw_measures' makes the sequence clear: this is the lookup step that feeds the measures tool. There is no explicit when-not or stated alternative for other station lookups, so it stops short of full routing guidance.

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