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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered, but the description adds real operational context: the 1,000-line limit, CSV+GeoJSON outputs, that download links build files lazily with nothing saved, and the caution not to feed those links to open_gis_file. It does not describe error handling for ambiguous lines, which keeps it short of a 5.

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-loads the 'Use this when...' trigger and packs the format list, detection caveats, output behavior, and exclusions into a dense but non-redundant block. It is long and parenthetical-heavy, which slightly hurts scannability, but nearly every clause earns its place.

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?

Even though an output schema exists (so return values need not be explained), the description covers input formats, detection limits, output artifacts, and the QGIS-oriented recommendation, leaving no material gap for a 3-parameter geospatial conversion tool.

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 the baseline is 3, but the description adds genuine routing logic the schema lacks: why source_epsg is needed (national grids the detector cannot disambiguate) and the auto-detection behavior including 'lat, lon' vs 'lon, lat' ordering. target_epsg is left to the schema.

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+resource (convert coordinates) and enumerates the exact formats supported (decimal degrees, DMS, UTM, MGRS, Lambert 93, EPSG). It also distinguishes itself from siblings, explicitly routing map/file handling to open_gis_file and CRS explanations away from this tool.

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 explicit when-to-use (user supplies coordinates wanting another system) and explicit when-not (conceptual CRS explanations, writing conversion code). It also documents the trigger condition for source_epsg (national grids like Dutch RD, Swiss LV95 where numbers alone are ambiguous).

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