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

With no annotations to lean on, the description carries the burden well: it discloses pricing/auth ($3/month, $1 for 24h via api_key or Bearer), a 1,000-line cap, and the confidence scale (high|medium|low|none). It does not describe rate limits or failure behavior, but the operational context is unusually rich.

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?

Every sentence carries information, but the front-loaded clause is pricing/auth rather than the tool's purpose, and the grammar is rambling in places. It is dense rather than wasteful, yet the ordering buries the core action.

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 spelled out, yet the description helpfully previews the JSON shape and candidate fields. Combined with auth, limits, and downstream routing, an agent has enough to call it correctly.

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 0%, so the description must compensate and largely does: it gives the exact `lines` row format ("P-7 690183.66, 4729859.76"), an example value for `country`, and confirms `api_key`'s two accepted forms. It only loosely frames `lat`/`lon` as location hints.

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 description conveys a specific verb (guessing/inferring) and resource (which CRS fits easting/northing rows), and it reinforces this with a concrete input example. It does not explicitly differentiate itself from the close sibling guess_crs_from_coordinates, leaving the agent to infer the boundary.

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?

It tells the agent what to supply to steer the guess (a `country` like "Kenya" or `lat`/`lon`) and names the downstream follow-up steps (reproject_geojson or /api/v1/crs/apply). It stops short of stating when NOT to use it or how it differs from guess_crs_from_coordinates / epsg_suggest.

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