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

With no annotations, the description carries the full burden and does a good job: it discloses that figures are sourced and dated, may be provisional, lists the permit-status enum values, explains that null means 'not recorded' when the feed lacks status, and states the server 'does not invent figures.' It also points to get_provenance and a record signature for verification.

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-loaded with the core purpose, but the back half sprawls across permit-status enums, null semantics, and provenance advice that read as loosely assembled caveats rather than tightly scoped statements. Most content is useful, but the structure is muddled.

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?

There is no output schema or annotations to lean on, and the description adequately covers the caveats an agent needs: data freshness/provisionality, null handling, enum values, and how to verify a figure via get_provenance. Some return-shape detail is absent, but the behavioral surface is well covered.

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?

The tool takes zero parameters, so there is nothing for the description to compensate for; the 4 baseline for a 0-param tool applies.

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 clear verb and resource: distinct region and country names on the /api/v1/trails endpoint, with the intent 'so an agent can see coverage.' It does not, however, differentiate itself from the sibling list_countries, leaving overlap ambiguous.

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?

Implies when to use it ('so an agent can see coverage') but never states when not to use it or names the obvious alternative, list_countries. Usage context is inferable rather than explicit.

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