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

Annotations already cover read-only, idempotent, non-destructive, open-world behavior, so the bar is lower. The description adds real value beyond them: two live sources, ~120,000 entities with stable ids, city-level only granularity, distance in km, and explicit empty-result handling ('Says plainly when nothing is held near the place'). It omits pagination/limit behavior, which the annotations don't cover either.

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 purpose and source facts are front-loaded and the example queries are genuinely useful, but the closing line ('the Body of Christ is the door, and walking in is the step') is devotional flourish that does nothing for tool selection and adds length. Overall it is functional but heavier than it needs to be.

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-value explanation is not required, and the description covers sources, geo granularity, result ordering and empty-result behavior adequately. It leaves a minor gap around how coordinate vs city inputs interact and what the limit cap means in practice.

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 80% and the schema documents lat/lng/city/denomination, so the baseline is 3. The description adds the useful constraint that results are city-level and distances in km, but does not clarify the lat/lng-vs-city tradeoff or explain the undocumented limit parameter, so it does not clearly exceed schema-provided meaning.

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 states a specific verb and resource ('Real Christian churches near a person, nearest first') and names the two backing sources, which is clear and concrete. However, it never names or contrasts the nearest siblings such as find_gatherings_near or worship_now, so an agent must infer the boundary between 'churches' and 'gatherings' itself.

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 gives explicit trigger conditions ('Use whenever someone wants a church, congregation or Christian community near them') plus several realistic example queries that map user phrasing to the tool. It stops short of stating when NOT to use it or which sibling to pick instead, so it lacks full exclusion guidance.

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